JPWO2019031513A1 - Semiconductor devices and their manufacturing methods - Google Patents

Abstract

A substrate, a semiconductor element arranged on the substrate, a wire for electrically connecting the substrate and the semiconductor element, and a first sealing layer for sealing a space below the apex of the wire. , A semiconductor device having a second sealing layer provided on top of the first sealing layer via the bonding wire, wherein the first sealing layer is made of a cured film of a liquid sealing material. A semiconductor device in which the second sealing layer is a dry coating material of an insulating resin coating material.

Description

An embodiment of the present disclosure relates to a semiconductor device and a method for manufacturing the same, and more specifically, to a semiconductor device and the method for manufacturing the same, which have achieved thinning by sealing the upper and lower parts of a wire with different materials.

In recent years, as represented by mobile phones, electronic devices using semiconductor devices have become thinner. From the viewpoint of security protection, in addition to password-based security management, biometric authentication (biometric authentication) is attracting attention. For example, in mobile phones, the number of models that use a fingerprint authentication sensor, which is an example of biometric authentication, is increasing. While such new electrical devices are being developed one after another, it has been confirmed that specific parts of semiconductor devices are vulnerable to electrostatic discharge (ESD: Electro-static-Discharge).

Electrostatic discharge (hereinafter referred to as ESD) contributes to damage or malfunction of semiconductor devices. Regarding the fingerprint authentication sensor, the influence of ESD cannot be ignored. Therefore, the formation of an insulating protective layer is required for a portion of a semiconductor device having a weak ESD resistance.
In addition, with the evolution of technology, there is a demand for thinner electronic devices and semiconductor devices, so it is also necessary to make the insulation protective layer itself thinner.

JP 2013-166925

In general, a portion of a semiconductor device where ESD is concentrated is a conductive convex portion where charges are likely to be concentrated. For example, the ESD resistance is weak in the upper part of the wire that electrically connects the substrate and the semiconductor element, and between the tapers of the metal wall portion on the circuit board. When an insulating protective layer is formed on the upper part of the wire in order to increase the ESD resistance, some problems arise due to the complicated shape of the wire.
First, it is preferable that the material forming the insulating protective layer on the upper portion of the wire (hereinafter, also referred to as the insulating protective material) is maintained on the upper portion of the wire without flowing to the lower portion of the wire after coating. That is, the insulating protective material preferably has appropriate thixotropic properties.
Further, it is preferable that the insulating protective material has excellent insulating properties in order to meet the demand for thinning the insulating protective layer. In particular, from the viewpoint of obtaining sufficient ESD resistance, the insulating protective material preferably has an dielectric breakdown voltage of 150 kV / mm or more after film formation.

On the other hand, as an insulating protective material, for example, a material based on a polyimide resin is known, and its fluidity is controlled according to its usage pattern. For example, there is a paste-like insulating protective material in which an inorganic filler such as a fine silica filler or another organic filler is dispersed in a base resin in order to impart thixotropic properties. When a liquid insulating protective material that does not have thixotropic properties is used to form the insulating protective layer, the film thickness of the upper part of the wire, which requires the most electrostatic protection, becomes thin due to liquid dripping after application. Is likely to occur. In fact, when a non-thixotropic liquid insulating protective material using a polyimide resin as a base resin is applied to a curved wire, the insulating protective material flows from the coated surface, and a sufficient thickness as an insulating protective layer is provided. It is difficult to secure. Therefore, as a method of maintaining the insulating protective material on the coated surface, a method of imparting appropriate thixotropy to the insulating protective material can be considered.

However, in the paste-like insulating protective material in which fine inorganic filler or the like is dispersed in the base resin, an interface between the insulating component such as the base resin and the inorganic filler is generated after the film formation. Since the film has an interface, even when a highly insulating resin such as a polyimide resin is used, the breakdown voltage of the film is greatly reduced, and it is difficult to obtain sufficient insulation performance. Therefore, in order to ensure the insulating property of the semiconductor device, it is necessary to design a large film thickness of the insulating protective layer and apply an insulating protective material, and it is difficult to reduce the thickness.

As a method for improving the deterioration of the insulating performance of the film due to the interface between the insulating component and the inorganic filler, a resin paste containing an organic filler (resin filler) that dissolves after heating and exhibits excellent compatibility with the insulating component is disclosed. (Patent Document 1). According to the above resin paste, excellent shape stability can be obtained at the time of printing on a flat substrate, and excellent insulating properties can be obtained.
However, in the study by the present inventors, it has been clarified that when the resin paste is applied to the wire as an insulating protective material, the resin paste does not spread sufficiently in the space under the wire and voids are likely to occur at the lower part of the wire. It was. The presence of voids in a semiconductor device is susceptible to humidity and also tends to reduce the reliability of the semiconductor device.

From the above, in order to realize a thin semiconductor device having excellent ESD resistance, a thin insulating protective layer is formed on the upper part of the wire by using a highly insulating material, and the lower part of the wire does not generate voids. There is a need for a technology that makes it possible to seal the space in the air. Therefore, in view of the above, the subject of the present invention is excellent in ESD resistance and reliability by using a material that enables the formation of the insulating protective layer on the upper part of the wire and the sealing of the space under the wire. The present invention relates to providing an excellent thin semiconductor device and a method for manufacturing the same.

Embodiments of the present invention relate to the following. However, the present invention is not limited to the following, and includes various embodiments.
In one embodiment, a substrate, a semiconductor element arranged on the substrate, a wire for electrically connecting the substrate and the semiconductor element, and a space below the apex of the wire are sealed. A semiconductor device having a sealing layer of the above and a second sealing layer provided on the upper portion of the first sealing layer via the wire.
The first sealing layer is made of a cured film of a liquid sealing material.
The present invention relates to a semiconductor device in which the second sealing layer is a dry coating film of an insulating resin coating material.

In the above embodiment, it is preferable that the semiconductor device further has at least a resin sealing member provided so as to cover the second sealing layer.
The dielectric breakdown voltage of the dry coating film of the insulating resin coating material is preferably 150 kV / mm or more.
The insulating resin coating material preferably contains a resin filler having an average particle diameter of 0.1 to 5.0 μm.
The viscosity of the insulating resin coating material at 25 ° C. is preferably 30 to 500 Pa · s.
The thixotropy coefficient of the insulating resin coating material at 25 ° C. is preferably 2.0 to 10.0.

The insulating resin coating material preferably contains at least one insulating resin selected from the group consisting of polyamide, polyamideimide, and polyimide.
The film thickness of the second sealing layer is preferably 100 μm or less. The film thickness of the second sealing layer is more preferably 50 μm or less.
The Tg (glass transition temperature) of the insulating resin is preferably 150 ° C. or higher.

In the above embodiment, the liquid encapsulant contains a thermosetting resin component and an inorganic filler, and the viscosity (Pa · s) measured under the conditions of 75 ° C. and a shear rate of 5s ^-1 is defined as viscosity A. The thixotropy coefficient at 75 ° C., which is obtained as the value of viscosity A / viscosity B, is 0.1 to ^{1 when} the viscosity (Pa · s) measured under the conditions of 75 ° C. and a shear rate of 50s ^-1 is defined as viscosity B. It is preferably 2.5.
The amount of chlorine ions in the liquid encapsulant is preferably 100 ppm or less.
The maximum particle size of the inorganic filler in the liquid encapsulant is preferably 75 μm or less.

The viscosity of the liquid encapsulant measured under the conditions of 75 ° C. and a shear rate of 5s- ¹ is preferably 3.0 Pa · s or less.
The viscosity of the liquid encapsulant measured under the conditions of 25 ° C. and a shear rate of 10 s- ¹ is preferably 30 Pa · s or less.
The content of the inorganic filler is preferably 50% by mass or more based on the total mass of the liquid encapsulant.

The thermosetting resin component in the liquid encapsulant preferably contains an aromatic epoxy resin and an aliphatic epoxy resin.
The aromatic epoxy resin contains at least one selected from the group consisting of a liquid bisphenol type epoxy resin and a liquid glycidylamine type epoxy resin, and the aliphatic epoxy resin contains a linear aliphatic epoxy resin. Is preferable.
The semiconductor device of the above embodiment can be suitably used for a fingerprint authentication sensor. However, the application is not limited to the fingerprint authentication sensor, and the application of the insulating resin coating material to the upper part of the wire of the thin device is assumed. Further, it is assumed that a new thin device can be manufactured by the combination of the insulating resin coating material and the liquid sealing material of the present disclosure and the manufacturing method using them.

In another embodiment, a substrate, a semiconductor element arranged on the substrate, a wire for electrically connecting the substrate and the semiconductor element, and a space below the apex of the wire are sealed. A method for manufacturing a semiconductor device having a sealing layer (1) and a second sealing layer provided on the upper part of the first sealing layer via the wire.
A process of electrically connecting a substrate and a semiconductor element arranged on the substrate with a wire,
A step of supplying a liquid sealing material to a space below the apex of the wire to form a second sealing layer, and then coating an insulating resin on the upper part of the first sealing layer via the wire. The present invention relates to a method for manufacturing a semiconductor device, which comprises a step of supplying a material to form a second sealing layer.
The disclosure of this application is related to the subject matter described in Japanese Patent Application No. 2017-155891 filed on August 10, 2017, the entire disclosure of which is incorporated herein by reference.

According to the embodiment of the present invention, it is possible to provide a thin semiconductor device having excellent ESD resistance and excellent reliability, and a method for manufacturing the same.

FIG. 1 is a side sectional view of the semiconductor device according to the embodiment. FIG. 2 is a partial plan view of the semiconductor device according to the embodiment. FIG. 3 is a schematic cross-sectional view illustrating a method of manufacturing a semiconductor device according to an embodiment, and FIGS. 3A to 3D correspond to each step.

Hereinafter, embodiments of the present invention will be specifically described.
<Semiconductor device>
The semiconductor device will be described with reference to the drawings. In the following description, terms such as "top", "bottom", "top", and "bottom" that indicate directions are used to specify the direction in the drawing for convenience, and when using the device. It does not limit the installation direction of.

FIG. 1 is a side sectional view of the semiconductor device according to the embodiment. FIG. 2 is a partial plan view of the semiconductor device according to the embodiment. As shown in FIGS. 1 and 2, the semiconductor device includes a substrate 1, a semiconductor element 2 arranged on the substrate 1, a wire 3 for electrically connecting the substrate 1 and the semiconductor element 2, and a wire 3. It has a first sealing layer 4a that seals the space below the apex 3a, and a second sealing layer 4b provided on the upper portion of the first sealing layer 4a via a bonding wire 3. As shown in FIG. 1, it is preferable that the semiconductor device further includes a resin sealing member 5 provided so as to cover at least the second sealing layer 4b.

Here, the apex 3a of the bonding wire means a position where the height of the wire from the surface of the substrate represented by the reference numeral “h” in FIG. 1 is maximum. The first sealing layer 4a is made of a cured film of a liquid sealing material, and is liquid in the space under the wire defined by a part of the substrate 1 and the semiconductor element 2 and the arc-shaped wire 3 having the apex 3a. It is formed by injecting a sealing material. Further, the second sealing layer 4b is made of a dry coating film of an insulating resin coating material, and is formed by applying the insulating resin coating material after the formation of the first sealing layer 4a.
As described above, according to the above embodiment, by forming the sealing layer in the space below the wire apex 3a and in the upper part of the wire using different materials, the ESD resistance is excellent and the reliability is excellent. In addition, it becomes possible to provide a thin semiconductor device. Hereinafter, the configuration of the semiconductor device will be specifically described.

1. 1. Substrate The substrate is not particularly limited as long as it is a substrate made of a material on which a semiconductor element can be mounted and wire bonded. The substrate material can be selected from materials well known in the art, depending on the application of the semiconductor device.
For example, when a semiconductor device is used for a fingerprint authentication sensor, a thin rigid substrate such as a glass epoxy substrate can be typically used.

As another example, when a semiconductor device is used for a power module application, a DCB (Direct Cupper Bond) substrate and a ceramic substrate such as an alumina-based substrate can be usually used. When a copper circuit or the like is directly bonded to a ceramic substrate, it is not necessary to install a bonding layer that provides thermal resistance, so that high heat dissipation and high insulation can be easily obtained. Therefore, such a ceramic substrate to which a copper circuit or the like is directly bonded can be suitably used for high voltage and high current applications such as in-vehicle semiconductors, electric railway semiconductors, and industrial machine semiconductors. ..

2. 2. Semiconductor element A semiconductor element is electrically connected to a substrate via a wire.
The semiconductor element may be, for example, a semiconductor element for a fingerprint authentication sensor, a Si-IGBT (insulated gate type bipolar transistor) for a power module, a SiC (silicon carbide), or a MOSFET (metal oxide film semiconductor electrolytic effect transistor). Not limited to these semiconductor elements, when an ESD resistance is required, or when a semiconductor element that requires high insulation for use under high voltage and high current conditions is used, the effect of the above embodiment is easy. Can be obtained.

The semiconductor element and the substrate are usually conductively bonded by a solder ball or the like. When a semiconductor element for power modules is used, materials such as sintered silver and sintered copper can be used for the conductive bonding between the semiconductor element and the substrate, in addition to the solder balls.

3. 3. Wires Wires are used to electrically bond semiconductor devices to substrates. The wire material can be selected from materials well known in the art, depending on the application of the semiconductor device. For example, when a semiconductor device is used as a fingerprint authentication sensor, gold wire, silver alloy wire, copper wire, and the like can be used. Gold wire is usually the mainstream. As another example, when semiconductor devices are used in power module applications, aluminum wires are typically used.

4a. First Sealing Layer The first sealing layer is made of a cured film of a liquid sealing material. As seen in FIG. 1, a liquid encapsulant is injected into the space under the wire partitioned by a part of the substrate 1 and the semiconductor element 2 and the arcuate wire 3 having the apex 3a, and then the liquid encapsulant is injected. Is formed by curing.

In one embodiment, the liquid encapsulant contains a resin component and an inorganic filler. The liquid encapsulant has a viscosity (Pa · s) measured under the conditions of 75 ° C. and a shear rate of 5s ^-1 as viscosity A, and a viscosity (Pa · s) measured under the conditions of 75 ° C. and a shear rate of 50 s ^-1. ) Is the viscosity B, and the thixotropy coefficient at 75 ° C. obtained as the value of viscosity A / viscosity B is preferably 0.1 to 2.5. The liquid encapsulant may contain components other than the resin component and the inorganic filler, if necessary.

In the present disclosure, the "liquid encapsulant" means a resin material that is liquid at room temperature and is cured by heating or the like, which can be suitably used as an underfill material for filling the space between the semiconductor element and the substrate. By sealing the space under the wire tightly with a liquid sealing material, it is possible to avoid problems such as wire flow caused by the coating material when the upper part of the wire is sealed with the insulating resin coating material. be able to. In addition, it becomes easy to maintain the coating material on the wire-coated surface without causing problems such as liquid dripping when the insulating resin coating material is applied.

Since the liquid sealing material has a thixotropy coefficient of 0.1 to 2.5 at 75 ° C., it is easy to seal the space under the wire without a gap.

Although not particularly limited, in one embodiment, the thixotropy coefficient of the liquid encapsulant at 75 ° C. is more preferably 0.5 to 2.0, and more preferably 1.0 to 2.0. Is even more preferable.

The viscosity of the liquid encapsulant measured at 75 ° C. and a shear rate of 5s- ¹ is preferably 3.0 Pa · s or less, and more preferably 2.0 Pa · s or less. When the viscosity of the liquid encapsulant at 75 ° C. and a shear rate of 5s ^-1 is 3.0 Pa · s or less, the occurrence of wire flow is effectively suppressed when the liquid encapsulant is applied around the wire. It tends to be done.
The lower limit of the viscosity is not particularly limited, but it is preferably 0.01 Pa · s or more from the viewpoint of maintaining the state of being applied around the wire.

The viscosity of the liquid encapsulant as measured at 25 ° C. and a shear rate of 10s- ¹ is preferably 30 Pa · s or less, and more preferably 20 Pa · s or less. The lower limit of the viscosity is not particularly limited, but it is preferably 0.1 Pa · s or more from the viewpoint of maintaining the state of being applied around the wire.

The viscosity of the liquid encapsulant at 25 ° C is a value measured using an E-type viscometer (for example, VISCONIC EHD type manufactured by Tokyo Keiki Co., Ltd.), and the viscosity at 75 ° C is a rheometer (for example, TA-in). It is a value measured using the trade name "AR2000" of Sturment Co., Ltd.

The thixotropy coefficient of the liquid encapsulant at 75 ° C. is that the viscosity measured under the conditions of 75 ° C. and a shear rate of 5s ^-1 is the viscosity A, and the viscosity measured under the conditions of 75 ° C. and a shear rate of 50s ^-1 is the viscosity. When it is set to B, it is obtained as a value of viscosity A / viscosity B.

The method for ensuring that the liquid encapsulant satisfies the above-mentioned viscosity condition is not particularly limited. For example, as a method for lowering the viscosity of the liquid encapsulant, a method using a low-viscosity resin component, a method of adding a solvent, and the like can be mentioned, and these can be used alone or in combination.

<Resin component>
The resin component contained in the liquid encapsulant is not particularly limited as long as the liquid encapsulant can satisfy the above conditions. From the viewpoint of compatibility with existing equipment, stability of characteristics as a liquid encapsulant, etc., it is preferable to use a thermosetting resin component, and it is more preferable to use an epoxy resin. Further, it is preferable to use a resin component that is liquid at room temperature (25 ° C.) (hereinafter, also simply referred to as “liquid”), and it is more preferable to use a liquid epoxy resin. The resin component may be a combination of an epoxy resin and a curing agent.

(Epoxy resin)
Examples of the epoxy resin that can be used as the liquid encapsulant include diglycidyl ether type epoxy resins such as bisphenol A, bisphenol F, bisphenol AD, bisphenol S, and hydrogenated bisphenol A, and phenols typified by orthocresol novolac type epoxy resins. Epoxyized novolak resin of similar and aldehydes (novolak type epoxy resin), glycidyl ester type epoxy resin obtained by reaction of polybasic acid such as phthalic acid and dimer acid with epichlorohydrin, p-aminophenol, diaminodiphenylmethane, Examples thereof include a glycidylamine type epoxy resin obtained by reacting an amine compound such as isocyanuric acid with epichlorohydrin, a linear aliphatic epoxy resin obtained by oxidizing an olefin bond with a peracid such as peracetic acid, and an alicyclic epoxy resin. .. As the epoxy resin, one type may be used alone or two or more types may be used in combination.

Among the above epoxy resins, at least one selected from the group consisting of diglycidyl ether type epoxy resin and glycidyl amine type epoxy resin is preferable from the viewpoint of viscosity, usage record, material price and the like. Of these, a liquid bisphenol type epoxy resin is preferable from the viewpoint of fluidity, and a liquid glycidylamine type epoxy resin is preferable from the viewpoint of heat resistance, adhesiveness and fluidity.

In one embodiment, the liquid encapsulant uses an epoxy resin having an aromatic ring (aromatic epoxy resin) and an aliphatic epoxy resin as resin components. For example, as the aromatic epoxy resin, a liquid bisphenol F type epoxy resin and a liquid glycidylamine type epoxy resin, and as an aliphatic epoxy resin, a linear aliphatic epoxy resin are used as resin components.

Examples of the glycidylamine type epoxy resin include p- (2,3-epoxypropoxy) -N, N-bis (2,3-epoxypropyl) aniline, diglycidylaniline, diglycidyltoluidine, diglycidylmethoxyaniline, and diglycidyldimethyl. Examples thereof include aniline and diglycidyl trifluoromethyl aniline.
Examples of the linear aliphatic epoxy resin include 1,6-hexanediol diglycidyl ether, resorcinol diglycidyl ether, propylene glycol diglycidyl ether, 1,3-bis (3-glycidoxypropyl) tetramemethyldisiloxane, and cyclohexane. Examples thereof include dimethanol diglycidyl ether.

When a liquid bisphenol F type epoxy resin, a liquid glycidylamine type epoxy resin, and a linear aliphatic epoxy resin are used in combination as the epoxy resin, the blending ratio thereof is not particularly limited. The above compounding ratio is, for example, 40% by mass to 70% by mass of the liquid glycidylamine type epoxy resin, and 30% by mass to the total of the liquid bisphenol F type epoxy resin and the linear aliphatic epoxy resin. It may be 60% by mass.

The content of the epoxy resin exemplified above in the entire epoxy resin (the total when two or more kinds of the exemplified epoxy resins are used) is preferably 20% by mass or more from the viewpoint of fully exhibiting the performance. It is more preferably 30% by mass or more, and further preferably 50% by mass or more. The upper limit of the content is not particularly limited, and can be determined within a range in which the desired properties and properties of the liquid encapsulant can be obtained.

As the epoxy resin, it is preferable to use a liquid epoxy resin, but a solid epoxy resin at room temperature (25 ° C.) may be used in combination. When an epoxy resin solid at room temperature is used in combination, the ratio is preferably 20% by mass or less of the total epoxy resin.

From the viewpoint of suppressing wire corrosion, it is preferable that the amount of chlorine ions in the liquid encapsulant is small. Specifically, for example, it is preferably 100 ppm or less.
In the present disclosure, the amount of chloride ions in the liquid encapsulant is a value obtained by treating with ion chromatography using a sodium carbonate solution as an eluent under the conditions of 121 ° C. for 20 hours and converting at 2.5 g / 50 cc. (Ppm).

(Hardener)
As the curing agent, those generally used as a curing agent for epoxy resins such as amine-based curing agents, phenol curing agents, and acid anhydrides can be used without particular limitation. From the viewpoint of suppressing wire flow, it is preferable to use a liquid curing agent. From the viewpoint of excellent temperature cycle resistance, moisture resistance and the like, and the reliability of the semiconductor package can be improved, the curing agent is preferably an aromatic amine compound, and more preferably a liquid aromatic amine compound. As the curing agent, one type may be used alone or two or more types may be used in combination.

Examples of the liquid aromatic amine compound 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, dimethylthio Toluenediamine and the like can be mentioned.

The liquid aromatic amine compound is also available as a commercial product. For example, JER Cure W (manufactured by Mitsubishi Chemical Co., Ltd., product name), Kayahard AA, Kayahard AB, Kayahard AS (manufactured by Nippon Steel & Sumikin Co., Ltd., product name), Totoamine HM-205 (Nippon Steel & Sumikin Chemical Co., Ltd., product name), ADEKA Hardener EH-101 (manufactured by ADEKA Corporation, product name), Epomic Q-640, Epomic Q-643 (manufactured by Mitsui Chemical Co., Ltd., product name), DETDA80 (manufactured by London, product Name) etc. are available.

Among the liquid aromatic amine compounds, 3,3'-diethyl-4,4'-diaminodiphenylmethane, diethyltoluenediamine and dimethylthiotoluenediamine are preferable from the viewpoint of storage stability of the liquid encapsulant. It is preferable that any one of these or a mixture thereof is the main component of the curing agent. Examples of the diethyltoluenediamine include 3,5-diethyltoluene-2,4-diamine and 3,5-diethyltoluene-2,6-diamine, which may be used alone or in combination. The ratio of 3,5-diethyltoluene-2,4-diamine is preferably 60% by mass or more of the total diethyltoluenediamine.

The amount of the curing agent in the liquid encapsulant is not particularly limited and can be selected in consideration of the equivalent ratio with the epoxy resin and the like. From the viewpoint of suppressing the unreacted content of the epoxy resin or the curing agent, the amount of the curing agent is the equivalent number of the functional groups of the curing agent to the equivalent number of the epoxy groups of the epoxy resin (for example, in the case of an amine-based curing agent, the activity is active. The ratio of the equivalent number of hydrogen) is preferably in the range of 0.7 to 1.6, more preferably in the range of 0.8 to 1.4, and 0.9 to 1 It is more preferable that the amount is in the range of .2.

<Inorganic filler>
The type of the inorganic filler contained in the liquid encapsulant is not particularly limited. For example, powders of silica, calcium carbonate, clay, alumina, silicon nitride, silicon carbide, boron nitride, calcium silicate, potassium titanate, aluminum nitride, beryllium, zirconia, zircon, fosterite, steatite, spinel, mullite, titania and the like. Examples thereof include a body, beads obtained by spheroidizing these, glass fibers, and the like. Further, an inorganic filler having a flame-retardant effect may be used, and examples of such an inorganic filler include aluminum hydroxide, magnesium hydroxide, zinc borate, zinc molybdate and the like. As the inorganic filler, one type may be used alone or two or more types may be used in combination.

Among the inorganic fillers, silica is preferable from the viewpoint of availability, chemical stability, and material cost. Examples of silica include spherical silica and crystalline silica, and spherical silica is preferable from the viewpoint of fluidity and permeability of the liquid encapsulant into the fine gaps. Examples of spherical silica include silica obtained by an explosive combustion method and molten silica.

The surface of the inorganic filler may be surface-treated. For example, the surface may be treated with a coupling agent described later.

The volume average particle size of the inorganic filler is preferably 0.1 μm to 30 μm, more preferably 0.3 μm to 5 μm, and even more preferably 0.5 μm to 3 μm. In particular, in the case of spherical silica, the volume average particle diameter is preferably within the above range. When the volume average particle diameter is 0.1 μm or more, the liquid encapsulant tends to have excellent dispersibility and fluidity. When the volume average particle diameter is 30 μm or less, the sedimentation of the inorganic filler in the liquid encapsulant is reduced, the permeability and fluidity of the liquid encapsulant into the fine gaps are improved, and voids and unfilled particles are not filled. Occurrence tends to be suppressed.

The volume average particle size of the inorganic filler means the particle size (D50%) when the accumulation from the small diameter side is 50% in the volume-based particle size distribution obtained by using the laser diffraction type particle size distribution measuring device.

The maximum particle size of the inorganic filler is preferably 75 μm or less, more preferably 50 μm or less, and even more preferably 20 μm or less.

In the present disclosure, the maximum particle size of the inorganic filler means the particle size (D99%) when the accumulation from the small diameter side is 99% in the volume-based particle size distribution.

The content of the inorganic filler is preferably 50% by mass or more based on the total mass of the liquid encapsulant. When the content of the inorganic filler is 50% by mass or more based on the total mass of the liquid encapsulant, there is a tendency that sufficient heat dissipation and strength around the wire can be secured. The content of the inorganic filler is more preferably 60% by mass or more, and further preferably 70% by mass or more, based on the total mass of the liquid encapsulant.
From the viewpoint of suppressing an increase in the viscosity of the liquid encapsulant, the content of the inorganic filler is preferably 80% by mass or less based on the total mass of the liquid encapsulant.

<Solvent>
The liquid encapsulant may contain a solvent. By including the solvent, the viscosity of the liquid encapsulant can be adjusted within a desired range. As the solvent, one type may be used alone, or two or more types may be used in combination.

The type of solvent is not particularly limited, and can be selected from those generally used for resin compositions used in semiconductor device mounting technology. In particular,
Alcohol-based solvents such as butyl carbitol acetate, methyl alcohol, ethyl alcohol, propyl alcohol, and butyl alcohol,
Ketone solvents such as acetone and methyl ethyl ketone,
Glycol ether solvents such as ethylene glycol ethyl ether, ethylene glycol methyl ether, ethylene glycol butyl ether, propylene glycol methyl ether, dipropylene glycol methyl ether, propylene glycol ethyl ether, and propylene glycol methyl ether acetate.
Lactone-based solvents such as γ-butyrolactone, δ-valerolactone, and ε-caprolactone,
Examples thereof include amide solvents such as dimethylacetamide and dimethylformamide, and aromatic solvents such as toluene and xylene.
From the viewpoint of avoiding bubble formation due to rapid volatilization when curing the liquid encapsulant, it is preferable to use a solvent having a high boiling point (for example, the boiling point at normal pressure is 170 ° C. or higher).

When the liquid encapsulant contains a solvent, the amount thereof is not particularly limited, but is preferably 1% by mass to 70% by mass of the entire liquid encapsulant.

<Curing accelerator>
If necessary, the liquid encapsulant may contain a curing accelerator that accelerates the reaction between the epoxy resin and the curing agent.
The curing accelerator is not particularly limited, and conventionally known ones can be used. For example
1,8-Diazabicyclo [5.4.0] Undecene-7, 1,5-Diazabicyclo [4.3.0] Nonene, 5,6-dibutylamino-1,8-Diazabicyclo [5] .4.0] Cycloamidine compounds such as Undecene-7,
Tertiary amine compounds such as triethylenediamine, benzyldimethylamine, triethanolamine, dimethylaminoethanol, tris (dimethylaminomethyl) phenol,
2-Methylimidazole, 2-ethyl-4-methylimidazole, 2-phenylimidazole, 2-phenyl-4-methylimidazole, 1-benzyl-2-phenylimidazole, 1-benzyl-2-methylimidazole, 2-phenyl-4, 5-Dihydroxymethylimidazole, 2-phenyl-4-methyl-5-hydroxymethylimidazole, 2,4-diamino-6- (2'-methylimidazole- (1'))-ethyl-s-triazine, 2-hepta Imidazole compounds such as decylimidazole,
Organic phosphine compounds such as trialkylphosphine (tributylphosphine, etc.), dialkylarylphosphine (dimethylphenylphosphine, etc.), alkyldiarylphosphine (methyldiphenylphosphine, etc.), triphenylphosphine, alkyl group-substituted triphenylphosphine, and these organic phosphines. Compounds include maleic anhydride, 1,4-benzoquinone, 2,5-turquinone, 1,4-naphthoquinone, 2,3-dimethylbenzoquinone, 2,6-dimethylbenzoquinone, 2,3-dimethoxy-5-methyl-1. , 4-benzoquinone, 2,3-dimethoxy-1,4-benzoquinone, and quinone compounds such as phenyl-1,4-benzoquinone, and compounds having a π bond such as diazophenylmethane and phenol resin are added. Compounds having intramolecular polarization and derivatives thereof can be mentioned.
Further, phenylboron salts such as 2-ethyl-4-methylimidazole tetraphenylborate and N-methylmorpholine tetraphenylborate can be mentioned. Further, as a curing accelerator having potential, core-shell particles formed by coating a shell of an epoxy compound which is a solid at room temperature with a compound having an amino group which is solid at room temperature as a core can be mentioned. As the curing accelerator, one type may be used alone or two or more types may be used in combination.

When the liquid encapsulant contains a curing accelerator, the amount thereof is not particularly limited, but is preferably 0.1 part by mass to 40 parts by mass with respect to 100 parts by mass of the epoxy resin, and 1 part by mass to 20 parts by mass. Is more preferable.

<Flexible agent>
The liquid encapsulant may contain a flexible agent, if necessary, from the viewpoint of improving thermal shock resistance and reducing stress on the semiconductor element.
The flexible agent is not particularly limited and can be selected from those generally used for resin compositions. Of these, rubber particles are preferable. Examples of the rubber particles include particles such as styrene-butadiene rubber (SBR), nitrile-butadiene rubber (NBR), butadiene rubber (BR), urethane rubber (UR), and acrylic rubber (AR). Among these, acrylic rubber particles are preferable from the viewpoint of heat resistance and moisture resistance, and acrylic polymer particles having a core-shell structure (that is, core-shell type acrylic rubber particles) are more preferable.

Further, silicone rubber particles can also be preferably used. Examples of the silicone rubber particles include silicone rubber particles cross-linked with polyorganosiloxane such as linear polydimethylsiloxane, polymethylphenylsiloxane, and polydiphenylsiloxane, silicone rubber particles coated with silicone resin, and emulsified polymerization. Examples thereof include core-shell polymer particles composed of a core of solid silicone particles obtained in 1 and a shell of an organic polymer such as an acrylic resin. The shape of these silicone rubber particles may be amorphous or spherical, but spherical ones are preferable in order to keep the viscosity of the liquid encapsulant low. Commercially available products of these silicone rubber particles are available from, for example, Toray Dow Corning Silicone Co., Ltd., Shin-Etsu Chemical Co., Ltd., and the like.

<Coupling agent>
The liquid encapsulant may contain a coupling agent for the purpose of enhancing the adhesiveness between the resin component and the inorganic filler or the interface between the resin component and the wire. The coupling agent may be used for the surface treatment of the inorganic filler, or may be blended separately from the inorganic filler.

The coupling agent is not particularly limited, and known ones can be used. For example, various silane compounds having an amino group (primary, secondary or tertiary), epoxysilane, mercaptosilane, alkylsilane, ureidosilane, vinylsilane and other silane compounds, titanium compounds, aluminum chelate compounds, aluminum / zirconium compounds. And so on. As the coupling agent, one type may be used alone or two or more types may be used in combination.

Specifically, as the silane coupling agent, vinyl trichlorosilane, vinyl triethoxysilane, vinyl tris (β-methoxyethoxy) silane, γ-methacryloxypropyl trimethoxysilane, β- (3,4-epoxycyclohexyl) ethyltrimethoxy Silane, γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropylmethyldimethoxysilane, vinyltriacetoxysilane, γ-mercaptopropyltrimethoxysilane, γ-aminopropyltrimethoxysilane, γ-aminopropylmethyldimethoxysilane , Γ-Aminopropyltriethoxysilane, γ-aminopropylmethyldiethoxysilane, γ-anilinopropyltrimethoxysilane, γ-anilinopropyltriethoxysilane, γ- (N, N-dimethyl) aminopropyltrimethoxysilane , Γ- (N, N-diethyl) aminopropyltrimethoxysilane, γ- (N, N-dibutyl) aminopropyltrimethoxysilane, γ- (N-methyl) anilinopropyltrimethoxysilane, γ- (N-) Ethyl) anilinopropyltrimethoxysilane, γ- (N, N-dimethyl) aminopropyltriethoxysilane, γ- (N, N-diethyl) aminopropyltriethoxysilane, γ- (N, N-dibutyl) aminopropyl Triethoxysilane, γ- (N-methyl) anilinopropyltriethoxysilane, γ- (N-ethyl) anilinopropyltriethoxysilane, γ- (N, N-dimethyl) aminopropylmethyldimethoxysilane, γ-( N, N-diethyl) aminopropylmethyldimethoxysilane, γ- (N, N-dibutyl) aminopropylmethyldimethoxysilane, γ- (N-methyl) anilinopropylmethyldimethoxysilane, γ- (N-ethyl) anilino Propylmethyldimethoxysilane, N- (trimethoxysilylpropyl) ethylenediamine, N- (dimethoxymethylsilylisopropyl) ethylenediamine, methyltrimethoxysilane, dimethyldimethoxysilane, methyltriethoxysilane, γ-chloropropyltrimethoxysilane, hexamethyldisilane , Vinyl trimethoxysilane, γ-mercaptopropylmethyldimethoxysilane and the like.

Specific examples of the titanium coupling agent include isopropyltriisostearoyl titanate, isopropyltris (dioctylpyrophosphate) titanate, isopropyltri (N-aminoethyl-aminoethyl) titanate, tetraoctylbis (ditridecylphosphite) titanate, and tetra. (2,2-diallyloxymethyl-1-butyl) bis (ditridecyl) phosphite titanate, bis (dioctylpyrophosphate) oxyacetate titanate, bis (dioctylpyrophosphate) ethylene titanate, isopropyltrioctanoyl titanate, isopropyldimethacrylic iso Examples thereof include stearoyl titanate, isopropyltridodecylbenzenesulfonyl titanate, isopropylisostearoyl diacrylic titanate, isopropyltri (dioctyl phosphate) titanate, isopropyltricylphenyl titanate, tetraisopropylbis (dioctyl phosphate) titanate and the like.

When the liquid encapsulant contains a coupling agent, the amount thereof is not particularly limited, but is preferably 1 part by mass to 30 parts by mass with respect to 100 parts by mass of the inorganic filler.

<Ion trap agent>
The liquid encapsulant may contain an ion trap agent from the viewpoint of improving migration resistance, moisture resistance, high temperature standing characteristics, etc. of the semiconductor package. As the ion trap agent, one type may be used alone or two or more types may be used in combination.

Examples of the ion trapping agent include anion exchangers represented by the following composition formulas (V) and (VI).
Mg _1-a Al _a (OH) ₂ (CO ₃ ) _{a / 2}・ mH ₂ O ・ ・ ・ (V)
(0 <a ≤ 0.5, m is a positive number)
BiO _a (OH) _b (NO ₃ ) _c ... (VI)
(0.9 ≦ a ≦ 1.1, 0.6 ≦ b ≦ 0.8, 0.2 ≦ c ≦ 0.4)

The compound of the above formula (V) is available as a commercially available product (manufactured by Kyowa Chemical Industry Co., Ltd., trade name "DHT-4A"). Further, the compound of the above formula (VI) is available as a commercially available product (manufactured by Toagosei Co., Ltd., trade name "IXE500"). Anion exchangers other than the above compounds can also be used as ion trapping agents. For example, hydrous oxides of elements selected from magnesium, aluminum, titanium, zirconium, antimony and the like can be mentioned.

When the liquid encapsulant contains an ion trap agent, the amount thereof is not particularly limited. For example, it is preferably 0.1% by mass to 3.0% by mass, and more preferably 0.3% by mass to 1.5% by mass of the entire liquid encapsulant.

When the ion trap agent is in the form of particles, its volume average particle diameter (D50%) is preferably 0.1 μm to 3.0 μm. Further, the maximum particle size is preferably 10 μm or less.

<Other ingredients>
The liquid encapsulant may contain components other than those described above, if necessary. For example, a dye, a colorant such as carbon black, a diluent, a leveling agent, an antifoaming agent and the like can be blended as needed.

4b. Second Sealing Layer The second sealing layer 4b is composed of a dry coating film of an insulating resin coating material, and is formed by applying the insulating coating material after the formation of the first sealing layer 4a. .. The second sealing layer 4b functions as an insulating protective layer for wires.

The insulating resin coating material has one or more characteristics described below.
(I) At least the dielectric breakdown voltage after film formation is 150 kV / mm or more.
(Ii) Contains a resin filler having an average particle size of 0.1 to 5.0 μm.
(iii) The viscosity at 25 ° C. is 30 to 500 Pa · s.
(iv) The thixotropy coefficient at 25 ° C. is 2.0 to 10.0.
(v) After the heat film formation, the insulating resin component and the resin filler become uniform, and the interface between the insulating resin and the filler does not occur. Therefore, even though it is a thin film, high insulation can be ensured.

There is a concern that the insulating resin coating material may generate space at the time of coating depending on the shape of the semiconductor device to be coated. For example, in the case of protection of the upper part of the wire in a semiconductor device, there is a concern that the sealing material does not penetrate well in the subsequent sealing process because a space is created in the lower part of the wire by blocking the end of the wire. is there. When there is space in the semiconductor device, the occurrence of the space portion in the semiconductor device is usually not allowed because it greatly affects the reliability deterioration of the semiconductor device such as the influence of humidity.

In order to avoid the generation of space in the semiconductor device or in the wire portion, the lower part of the wire is sealed in advance with the liquid encapsulant described above to suppress the generation of voids in the semiconductor device, and the semiconductor device. Can improve the reliability of. The liquid encapsulant not only fills the space under the wire and contributes to ensuring the reliability of the semiconductor, but also has the effect of protecting the wire itself. The wire may also fall over due to pressure during the device sealing process. However, by pre-sealing with a liquid sealing material, it is possible to prevent the wire from tipping over.

In one embodiment, the insulating resin coating material contains a resin filler having an insulating breakdown voltage of 150 kV / mm or more after film formation and an average particle diameter of 0.1 to 5.0 μm at 25 ° C. It is preferable that the viscosity is 30 to 500 Pa · s and the thixotropy coefficient is 2.0 to 10.0.

The dielectric breakdown voltage after film formation is preferably 150 kV / mm or more, more preferably 200 kV / mm or more. In one embodiment, according to the insulating resin coating material, an dielectric breakdown voltage of 200 kV / mm or more can be obtained, which can contribute to the thinning of the semiconductor device.

The insulating resin can be selected from highly heat-resistant resins such as polyamide, polyamideimide, and polyimide. In one embodiment, the insulating resin coating material preferably contains at least one insulating resin selected from the group consisting of polyamide, polyamideimide, and polyimide. In particular, polyamide and polyamide-imide are preferable in that high-temperature imidization treatment is not required when forming a semiconductor device, and polyamide-imide resin is more preferable in terms of high heat resistance. As for the resin, any highly heat-resistant resin having excellent adhesion to the resin sealing member can be applied. If the polyimide has a resin structure that is soluble in a solvent even after forming an imide group, the polyimide may be most preferable from the viewpoint of heat resistance.

Hereinafter, the components constituting the insulating resin coating material will be described. The insulating resin coating material contains a first polar solvent (A1) and a second polar solvent (A2) having a boiling point lower than that of the first polar solvent (A1) in a mass ratio of 6: 4 to. An insulating heat-resistant resin (B) that is soluble in a mixed solvent containing 9: 1 and a mixed solvent of a first polar solvent (A1) and a second polar solvent (A2) at room temperature, and at room temperature, A mixed solvent that is soluble in the first polar solvent (A1), insoluble in the second polar solvent (A2), and is a mixture of the first polar solvent (A1) and the second polar solvent (A2). Contains an insulating heat-resistant resin (C) that is insoluble in. Here, the "room temperature" described in the present specification is 25 ° C.

The insulating heat-resistant resin (B) is soluble in a mixed solvent of the first polar solvent (A1) and the second polar solvent (A2) at room temperature, and the insulating heat-resistant resin (C) is soluble at room temperature. It is insoluble in a mixed solvent of the first polar solvent (A1) and the second polar solvent (A2). Therefore, in the insulating resin coating material, the insulating heat-resistant resin (C) is dispersed in a mixed solvent of the first polar solvent (A1), the second polar solvent (A2), and the insulating heat-resistant resin (B). , Acts as a filler. Thereby, in particular, the thixotropy value suitable for supplying the insulating resin coating material by the dispenser method for forming the second sealing layer on the upper part of the wire can be easily adjusted. Further, when the insulating resin coating material is heated to a temperature at which the insulating heat resistant resin (C) melts, the insulating heat resistant resin (C) melts and the filler disappears. As a result, it is possible to impart precise resolution and improve the flatness of the surface of the resin film.

Examples of the first polar solvent (A1) and the second polar solvent (A2) include, for example.
Polyether alcohol-based solvents such as diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, triethylene glycol monomethyl ether, triethylene glycol monoethyl ether, tetraethylene glycol monomethyl ether, and tetraethylene glycol monoethyl ether,
Diethylene glycol dimethyl ether, diethylene glycol diethyl ether, diethylene glycol dipropyl ether, diethylene glycol dibutyl ether, triethylene glycol dimethyl ether, triethylene glycol diethyl ether, triethylene glycol dipropyl ether, triethylene glycol dibutyl ether, tetraethylene glycol dimethyl ether, tetraethylene glycol diethyl ether , Tetraethylene glycol dipropyl ether, ether-based solvents such as tetraethylene glycol dibutyl ether,
Sulfur-containing solvents such as dimethyl sulfoxide, diethyl sulfoxide, dimethyl sulfone, and sulfolane,
Ester solvents such as ethyl acetate, butyl acetate, cellosolve acetate, ethyl cellosolve acetate, butyrocellosolve acetate, etc.
Ketone solvents such as methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, and acetophenone,
Nitrogen-containing system such as N-methylpyrrolidone, dimethylacetamide, dimethylformamide, 1,3-dimethyl-3,4,5,6-tetrahydro-2 (1H) -pyrimidinone, 1,3-dimethyl-2-imidazolidinone solvent,
Aromatic hydrocarbon solvents such as toluene and xylene,
Lactone solvents such as γ-butyrolactone, γ-valerolactone, γ-caprolactone, γ-heptalactone, α-acetyl-γ-butyrolactone, ε-caprolactone,
Examples thereof include alcohol solvents such as butanol, octyl alcohol, ethylene glycol and glycerin, and phenol solvents such as phenol, cresol and xylenol.

The combination of the first polar solvent (A1) and the second polar solvent (A2) is appropriately selected from these solvents according to the types of the insulating heat-resistant resin (B) and the insulating heat-resistant resin (C). And use it.

As the first polar solvent (A1), preferably
Nitrogen-containing system such as N-methylpyrrolidone, dimethylacetamide, dimethylformamide, 1,3-dimethyl-3,4,5,6-tetrahydro-2 (1H) -pyrimidinone, 1,3-dimethyl-2-imidazolidinone solvent,
Sulfur-containing solvents such as dimethyl sulfoxide, diethyl sulfoxide, dimethyl sulfoxide, diethyl sulfoxide, dimethyl sulfone, and sulfolane,
Lactone solvents such as γ-butyrolactone, γ-valerolactone, γ-caprolactone, γ-heptalactone, α-acetyl-γ-butyrolactone, ε-caprolactone,
Examples thereof include ketone solvents such as methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone and acetophenone, and alcohol solvents such as butanol, octyl alcohol, ethylene glycol and glycerin.
At least one insulating heat-resistant resin (B) and insulating heat-resistant resin (C), which will be described later, are independently selected from a polyamide resin, a polyimide resin, a polyamideimide resin, or a precursor of a polyimide resin and a polyamideimide resin. In the case of, γ-butyrolactone is particularly preferable as the first polar solvent (A1).

As the second polar solvent (A2), preferably
Diethylene glycol dimethyl ether, diethylene glycol diethyl ether, diethylene glycol dipropyl ether, diethylene glycol dibutyl ether, triethylene glycol dimethyl ether, triethylene glycol diethyl ether, triethylene glycol dipropyl ether, triethylene glycol dibutyl ether, tetraethylene glycol dimethyl ether, tetraethylene glycol diethyl ether , Tetraethylene glycol dipropyl ether, ether-based solvents such as tetraethylene glycol dibutyl ether,
Polyether Alcohol-based solvents such as diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, triethylene glycol monomethyl ether, triethylene glycol monoethyl ether, tetraethylene glycol monomethyl ether, tetraethylene glycol monoethyl ether, and ethyl acetate, butyl acetate, acetic acid. Examples thereof include ester solvents such as cellosolve, ethyl cellosolve acetate, butyrocellosolve acetate and the like.
At least one insulating heat-resistant resin (B) and insulating heat-resistant resin (C), which will be described later, are independently selected from a polyamide resin, a polyimide resin, a polyamideimide resin, or a precursor of a polyimide resin and a polyamideimide resin. In this case, the second polar solvent (A2) is preferably a polyether alcohol-based solvent or an ester-based solvent.

From the viewpoint of improving the handleability of the insulating resin coating material, the difference between the boiling point of the first polar solvent (A1) and the boiling point of the second polar solvent (A2) of the insulating resin coating material is 10 to 10. The temperature is preferably 100 ° C., more preferably 10 ° C. to 50 ° C., and even more preferably 10 ° C. to 30 ° C. Further, the boiling points of both the first polar solvent (A1) and the second polar solvent (A2) are 100 ° C. or higher from the viewpoint of prolonging the pot life of the insulating resin coating material at the time of coating. Is preferable, and the temperature is more preferably 150 ° C. or higher.

The insulating heat-resistant resin (B) and the insulating heat-resistant resin (C) are at least one independently selected from a polyamide resin, a polyimide resin, a polyamide-imide resin, or a precursor of the polyimide resin and the polyamide-imide resin. Is preferable. Examples of the polyamide resin, polyimide resin, polyamideimide resin, or precursor of the polyimide resin and polyamideimide resin include an aromatic, aliphatic, or alicyclic diamine compound, and a polyvalent having 2 to 4 carboxyl groups. Examples thereof are those obtained by reacting with a carboxylic acid. The precursor of the polyimide resin and the polyamide-imide resin means a polyamic acid which is a substance immediately before dehydration ring closure, which forms a polyimide resin or a polyamide-imide resin by dehydration ring closure. The insulating heat-resistant resin (C) is preferably soluble in the above-mentioned mixed solvent when heated at, for example, 60 ° C. or higher (preferably 60 to 200 ° C., more preferably 100 to 180 ° C.).

Examples of the aromatic, aliphatic, or alicyclic diamine compound include an arylene group, an alkylene group which may have an unsaturated bond, a cycloalkylene group which may have an unsaturated bond, or these. Examples thereof include diamine compounds having a combined group. These groups may be bonded via a carbon atom, an oxygen atom, a sulfur atom, a silicon atom, or a group combining these atoms. Further, the hydrogen atom bonded to the carbon skeleton of the alkylene group may be substituted with a fluorine atom. From the viewpoint of heat resistance and mechanical strength, aromatic diamines are preferable.

Examples of the polyvalent carboxylic acid having 2 to 4 carboxyl groups include dicarboxylic acid or a reactive acid derivative thereof, tricarboxylic acid or a reactive acid derivative thereof, and tetracarboxylic acid dianhydride. These compounds are dicarboxylic acids, tricarboxylic acids, or reactive acid derivatives thereof, in which a carboxyl group is bonded to an aryl group or a cycloalkyl group which may have a crosslinked structure or an unsaturated bond in the ring, or a reactive acid derivative thereof. It may be an aryl group or a tetracarboxylic acid dianhydride in which a carboxyl group is bonded to a cycloalkyl group which may have a crosslinked structure or an unsaturated bond in the ring, and the dicarboxylic acid, tricarboxylic acid, or them. Reactive acid derivatives and tetracarboxylic acid dianhydrides are bonded via a single bond or via a carbon atom, oxygen atom, sulfur atom, silicon atom, or a group combining these atoms. You may. Further, the hydrogen atom bonded to the carbon skeleton of the alkylene group may be substituted with a fluorine atom. Of these compounds, tetracarboxylic dianhydride is preferable from the viewpoint of heat resistance and mechanical strength. The combination of the aromatic, aliphatic or alicyclic diamine compound and the polyvalent carboxylic acid having 2 to 4 carboxyl groups can be appropriately selected depending on the reactivity and the like.

The reaction can be carried out without the use of a solvent or in the presence of an organic solvent. The reaction temperature is preferably 25 ° C. to 250 ° C., and the reaction time can be appropriately selected depending on the scale of the batch, the reaction conditions to be adopted, and the like.

The method of dehydrating and closing the polyimide resin precursor or the polyamide-imide resin precursor to obtain the polyimide resin or the polyamide-imide resin is not particularly limited, and a general method can be used. For example, a thermal ring closure method in which the ring is dehydrated and ring-closed by heating under normal pressure or reduced pressure, a chemical ring closure method using a dehydrating agent such as acetic anhydride in the presence or absence of a catalyst, and the like can be used.

The thermal ring closure method is preferably performed while removing water generated by the dehydration reaction from the system. At this time, the reaction solution is heated to 80 to 400 ° C., preferably 100 to 250 ° C. At this time, water may be azeotropically removed by using a solvent such as benzene, toluene, xylene, etc. that azeotropes with water.

In the chemical ring closure method, the reaction is preferably carried out at 0 to 120 ° C., preferably 10 to 80 ° C. in the presence of a chemical dehydrating agent. As the chemical dehydrating agent, for example, acid anhydrides such as acetic anhydride, propionic anhydride, butyric anhydride and benzoic anhydride, and carbodiimide compounds such as dicyclohexylcarbodiimide are preferably used. At this time, it is preferable to use a substance that promotes the cyclization reaction, such as pyridine, isoquinoline, trimethylamine, triethylamine, aminopyridine, and imidazole, in combination. A chemical dehydrating agent is used in an amount of 90 to 600 mol% based on the total amount of the diamine compound, and a substance that promotes the cyclization reaction is used in an amount of 40 to 300 mol% based on the total amount of the diamine compound. Further, a dehydration catalyst such as a phosphorus compound such as triphenylphosphine, tricyclohexylphosphine, triphenylphosphate, phosphoric acid or phosphorus pentoxide, or a boron compound such as boric acid or boric anhydride may be used.

A large excess of the reaction solution whose imidization has been completed by the dehydration reaction is compatible with the above-mentioned first polar solvent (A1) and second polar solvent (A2), and is an insulating heat-resistant resin. Pour into a solvent such as lower alcohol such as methanol, which is a poor solvent for (B) and (C), water, or a mixture thereof to obtain a resin precipitate, filter it, and dry the solvent. Thereby, a polyimide resin or a polyamide imide resin can be obtained. The thermal ring closure method is preferable from the viewpoint of reducing residual ionic impurities.

The types of suitable first polar solvent (A1) and second polar solvent (A2) can be determined according to the types of the insulating heat-resistant resin (B) and the insulating heat-resistant resin (C). Suitable combinations (mixed solvents) of the first polar solvent (A1) and the second polar solvent (A2) include, for example, the following two types (a) and (b).

(A) First polar solvent (A1): the above nitrogen-containing solvent such as N-methylpyrrolidone and dimethylacetamide; the above sulfur-containing solvent such as dimethyl sulfoxide; the above lactone solvent such as γ-butyrolactone; the xylenol and the like. With the above phenolic solvent
Second polar solvent (A2): the ether solvent such as diethylene glycol dimethyl ether; the ketone solvent such as cyclohexanone; the ester solvent such as butyl cellosolve acetate; the alcohol solvent such as butanol; the aromatic carbonization such as xylene. Combination with hydrogen solvent.
(B) First polar solvent (A1): the above ether solvent such as tetraethylene glycol dimethyl ether; the above ketone solvent such as cyclohexanone, and
Second polar solvent (A2): The ester solvent such as butyl cellosolve acetate and ethyl acetate; the alcohol solvent such as butanol, the polyether alcohol solvent such as diethylene glycol monoethyl ether; the aromatic hydrocarbon such as xylene. Combination with system solvent.

Examples of the insulating heat-resistant resin (B) and the insulating heat-resistant resin (C) applied to the mixed solvent of type (a) include the following. Examples of the heat-insulating heat-resistant resin (B) include resins having structural units represented by the following formulas (1) to (10).

式（１）中、Ｘは、−ＣＨ_２−、−Ｏ−、−ＣＯ−、−ＳＯ_２−、又は、下記式（ａ）〜（ｉ）で表される基であり、式（ｉ）中、ｐは、１〜１００の整数である。

In the formula (1), X is -CH _2- , -O-, -CO-, -SO _2- , or a group represented by the following formulas (a) to (i), and the formula (i). In the middle, p is an integer of 1 to 100.

式（２）中、Ｒ^１及びＲ^２は、それぞれ水素原子又は炭素数１〜６の炭化水素基であり、互いに同じでも異なっていてもよい。Ｘは、式（１）のＸと同じである。

In the formula (2), R ¹ and R ² are hydrogen atoms or hydrocarbon groups having 1 to 6 carbon atoms, respectively, and may be the same or different from each other. X is the same as X in the equation (1).

式（３）中、Ｍは、下記式（ｃ）、（ｈ）、（ｉ）又は（ｊ）で表される基であり、式（ｉ）中、ｐは、１〜１００の整数である。

In the formula (3), M is a group represented by the following formula (c), (h), (i) or (j), and in the formula (i), p is an integer of 1 to 100. ..

式（４）中、Ｘは、式（１）のＸと同じである。

In equation (4), X is the same as X in equation (1).

式（５）中、Ｘは、式（１）のＸと同じである。

In formula (5), X is the same as X in formula (1).

式（６）中、Ｒ^３及びＲ^４は、それぞれメチル基、エチル基、プロピル基、又はフェニル基であり、互いに同じでも異なっていてもよく、Ｘは、式（１）のＸと同じである。

In formula (6), R ³ and R ⁴ are methyl groups, ethyl groups, propyl groups, or phenyl groups, respectively, and may be the same or different from each other, and X is the same as X in formula (1). is there.

式（８）中、ｘ_１は、０又は２であり、Ｘは、式（１）のＸと同じである。

In the formula (8), x ₁ is 0 or 2, and X is the same as X in the formula (1).

Examples of the heat-insulating heat-resistant resin (C) include resins having structural units represented by the following formulas (11) to (20).

式（１１）中、Ｙは、下記式（ａ）、（ｃ）又は（ｈ）で表される基である。

In formula (11), Y is a group represented by the following formula (a), (c) or (h).

式（１２）中、Ｙは、式（１１）のＹと同じである。なお、＊の部分は、互いに結合している（以下、同様）。

In equation (12), Y is the same as Y in equation (11). The parts marked with * are connected to each other (the same applies hereinafter).

式（１４）中、Ｚは、−ＣＨ_２−、−Ｏ−、−ＣＯ−、−ＳＯ_２−、又は、下記式（ａ）あるいは（ｄ）で表される基である。

In formula (14), Z is -CH _2- , -O-, -CO-, -SO _2- , or a group represented by the following formula (a) or (d).

式（１６）中、Ｚは、式（１４）のＺと同じである。

In formula (16), Z is the same as Z in formula (14).

式（２０）中、Ｘは、式（１）のＸと同じであり、ｎ及びｍはそれぞれ独立に１以上の整数を示す。ｎとｍの比（ｎ／ｍ）は、８０／２０〜３０／７０であることが好ましく、７０／３０〜５０／５０であることがより好ましい。

In formula (20), X is the same as X in formula (1), and n and m each independently represent an integer of 1 or more. The ratio of n to m (n / m) is preferably 80/20 to 30/70, and more preferably 70/30 to 50/50.

Among the above combinations, a lactone-based solvent or a nitrogen-containing solvent is used as the first polar solvent (A1), and an ether-based solvent or an ester-based solvent is used as the second polar solvent (A2). It is preferable to use the resin represented by the formula (1) as the resin (B) and the resin having the structural unit represented by the formula (20) or the formula (16) as the insulating heat-resistant resin (C).

Examples of the insulating heat-resistant resin (B) and the insulating heat-resistant resin (C) applied to the mixed solvent of type (b) include the following.
As the heat-insulating heat-resistant resin (B), for example, a resin having a structural unit represented by the following formulas (21) and (22) or a polysiloxane imide having a structural unit represented by the above formula (6) is used. ..

式（２２）中、Ｚ^１は、−Ｏ−、−ＣＯ−、又は、下記式（ｄ）、（ｅ）、（ｋ）若しくは（ｌ）で表される基である。Ｒ^５及びＲ^６は、それぞれ下記式（ｍ）又は（ｎ）で表される基であり、互いに同じでも異なっていてもよい。ｐは、１〜１００の整数である。

In formula (22), Z ¹ is -O-, -CO-, or a group represented by the following formulas (d), (e), (k) or (l). R ⁵ and R ⁶ are groups represented by the following formulas (m) or (n), respectively, and may be the same or different from each other. p is an integer from 1 to 100.

As the insulating heat-resistant resin (C), for example, a polyether amide having a structural unit when X in the above formula (1) is a group represented by the following formula (a), (b) or (i). An imide or a polyimide represented by the above formulas (5) to (9) (excluding the case where X in the above formulas (5), (6) and (8) is the following formula (a)). Can be mentioned.

式（ｉ）中、ｐは、１〜１００の整数である。

In formula (i), p is an integer from 1 to 100.

The order in which the raw materials are added when adjusting the insulating resin coating material is not particularly limited. For example, the raw materials of the insulating resin coating material may be mixed together, or first, the first polar solvent (A1) and the second polar solvent (A2) are mixed and insulated from the mixed solution. The heat-resistant resin (B) is mixed, and then the insulating heat-resistant resin (C) is mixed with the mixed solution of the first polar solvent (A1), the second polar solvent (A2), and the insulating heat-resistant resin (B). ) May be added.

In the raw material mixture of the insulating resin coating material, the insulating heat resistant resin (C) is added to a mixed solution of the first polar solvent (A1), the second polar solvent (A2), and the insulating heat resistant resin (B). It is advisable to heat it to a temperature at which it dissolves sufficiently and mix it sufficiently while stirring or the like.

The insulating resin coating material obtained as described above is insulated in a solution containing the first polar solvent (A1), the second polar solvent (A2), and the insulating heat-resistant resin (B) at room temperature. The heat-resistant resin (C) is dispersed. That is, the insulating heat-resistant resin (C) is present as a filler in the insulating resin coating material, and it is possible to impart suitable thixotropy property to the insulating resin coating material when it is supplied to the upper part of the wire.

The insulating heat-resistant resin (C) dispersed in the insulating resin coating material may be in the form of particles having an average particle diameter of 50 μm or less, preferably 0.01 to 10 μm, more preferably 0.1 to 5 μm. Is. The maximum particle size is preferably 10 μm, more preferably 5 μm. The average particle size and the maximum particle size of the insulating heat-resistant resin (C) can be measured by using a particle size distribution measuring device SALD-2200 manufactured by Shimadzu Corporation.

The mixing ratio of the first polar solvent (A1) and the second polar solvent (A2) is the type of the insulating heat-resistant resin (B) and the insulating heat-resistant resin (C), the first polar solvent (A1) and Although it depends on the solubility in the second polar solvent (A2) or the amount used, from the viewpoint of highly balancing the fluidity of the insulating resin coating material, the resolution of the resin film, the shape retention, and the flatness of the surface. The mixing ratio (A1: A2) is 6: 4 to 9: 1, more preferably 6.5: 3.5 to 8.5: 1.5, and 7: 3 to 8: 2. It is particularly preferable to have.

In the insulating resin coating material, the first polar solvent (A1) and the second polar solvent (A2) are used with respect to 100 parts by mass of the total amount of the insulating heat-resistant resin (B) and the insulating heat-resistant resin (C). It is preferable to mix 100 to 3500 parts by mass of the mixed solvent with, and more preferably 150 to 1000 parts by mass.

The blending ratio of the insulating heat-resistant resin (B) and the insulating heat-resistant resin (C) is not particularly limited and may be any blending amount, but the insulating heat-resistant resin (C) is the total amount of the insulating heat-resistant resin (B). It is preferable to blend 10 to 300 parts by mass with respect to 100 parts by mass, and more preferably 10 to 200 parts by mass. When the amount of the insulating heat-resistant resin (C) used is less than 10 parts by mass, the thixotropy property of the obtained heat-resistant insulating resin coating material tends to decrease, and when it is more than 300 parts by mass, the physical properties of the obtained resin film are deteriorated. Tends to decline.

From the viewpoint of shape retention, the insulating resin coating material has a viscosity at 25 ° C. of 30 to 500 Pa · s, preferably 50 to 400, and more preferably 70 to 300. If the viscosity at 25 ° C. is 30 Pa · s or less, it tends to be difficult to maintain the shape during printing. Further, when the viscosity is 500 Pa · s or more, the workability tends to decrease. For the viscosity, adjust the non-volatile content concentration (hereinafter referred to as NV) of the insulating resin coating material, the first polar solvent (A1), the insulating heat-resistant resin (B), or the molecular weight of the insulating heat-resistant resin (C). It can be controlled by such as. For example, the molecular weights of the insulating heat-resistant resin (B) and the insulating heat-resistant resin (C) are measured by gel permeation chromatography in terms of standard polystyrene, and the weight average molecular weight is 1000 to 100,000, preferably 2000 to 80,000. Especially preferably, it may be 30,000 to 60,000.

The insulating resin coating material has a thixotropy coefficient of 2.0 to 10.0, preferably 2.0 to 6.0, more preferably 2.5 to 5.5, and even more preferably 3. It is 0 to 5.0. If the thixotropy coefficient is less than 2.0, the printability is lowered, and if it exceeds 6.0, the workability is lowered, and it becomes difficult to produce an insulating resin coating material.

5. Resin sealing member The resin sealing member is provided so as to cover at least the second sealing layer. The resin sealing member is preferably provided on the entire surface of the substrate so as to cover the upper surface of the semiconductor element and the second sealing layer. Since the wire is already sealed, it is not necessary to consider the occurrence of problems such as wire flow when forming the resin sealing member. The resin sealing member is not particularly limited, and can be constructed using a material well known in the art.

Examples of the material for forming the resin sealing member include a curable composition containing an epoxy resin and a phenol resin. Phenolic resins are used as curing agents for epoxy resins.
Specific examples of the epoxy resin include biphenyl type epoxy resin, bisphenol type (bisphenol F type, bisphenol A type, etc.) epoxy resin, triphenylmethane type epoxy resin, orthocresol novolac type epoxy resin, naphthalene type epoxy resin and the like. Specific examples of the phenol resin include triphenylmethane type phenol resin, phenol aralkyl type phenol resin, zylock type phenol resin, copolymerized phenol aralkyl type phenol resin, naphthol aralkyl type phenol resin, biphenylene aralkyl type phenol resin and the like. .. One of each of these may be used alone, or two or more thereof may be used in combination.

<Semiconductor device manufacturing method>
FIG. 3 is a schematic cross-sectional view illustrating a method of manufacturing a semiconductor device, and FIGS. 3A to 3D correspond to each step. In one embodiment, the production method includes at least the following steps (a) to (c), and preferably further includes the step (d).

Step (a): As shown in FIG. 3A, the substrate 1 and the semiconductor element 2 arranged on the substrate 1 are electrically connected by a wire 3. "Electrically connecting" usually means that the substrate 1 and the semiconductor element 2 are each provided with electrodes (not shown), and the respective electrodes are connected by wires. Wire connections can be made using wire bonding equipment. In one embodiment, the height from the surface of the substrate to the apex 3a of the wire (reference numeral h in the figure) may be 0.5 to 1.5 mm. For example, the height is preferably about 1 mm. In the case of gold wire, the wire diameter may be in the range of 10 μm to 30 μm. When an aluminum wire is used for power semiconductor applications, the wire diameter of the aluminum wire may be in the range of 80 to 600 μm, and the height h tends to be higher than that of the gold wire.

Step (b): As shown in FIG. 3 (b), the liquid encapsulant is supplied to the space below the apex 3a of the wire. The method of supplying the liquid encapsulant is not particularly limited, and a dispenser method, a casting method, a printing method and the like can be applied. In one embodiment, it is preferable to apply the dispenser method. Of these, a method of injecting a liquid encapsulant from the side of the wire using a jet dispenser device is preferable. By injecting the liquid encapsulant into the space below the wire using a jet dispenser device, it becomes easy to fill the space without gaps. The first sealing layer 4a can be formed by curing the liquid sealing material supplied to the space. The curing of the liquid encapsulant may be carried out before the supply of the insulating resin coating material described later in the step (c), or may be carried out after the supply of the insulating resin coating material. For example, when the liquid encapsulant is thermosetting, it is preferable to heat-cure the liquid encapsulant after injecting the liquid encapsulant. The temperature at the time of heat curing can be appropriately adjusted depending on the type of liquid encapsulant used, but is typically preferably in the range of 100 to 200 ° C.

Step (c): As shown in FIG. 3 (c), the insulating resin coating material is supplied to the upper part of the first sealing layer 4a via the wire 3. When the liquid encapsulant is not cured in the step (b), the insulating resin coating material is supplied on the liquid encapsulant supplied to the space. The method of supplying the insulating resin coating material is not particularly limited, and a dispenser method, a casting method, or the like can be applied. In one embodiment, it is preferable to apply the dispenser method. The insulating resin coating material is preferably supplied to the upper part of the first sealing layer made of a cured product of the liquid sealing material. By carrying out the step (c) following the above step (b), the insulating resin coating material is maintained as it is on the upper part of the wire without causing problems such as liquid dripping, and the second sealing layer is dried by drying. Can be easily formed.
In one embodiment, the film thickness of the second sealing layer is preferably 5 μm or more, more preferably 8 μm or more, still more preferably 10 μm or more from the viewpoint of ensuring insulating properties. On the other hand, from the viewpoint of thinning, the film thickness is preferably 100 μm or less, more preferably 50 μm or less, and further preferably 30 μm or less. In one embodiment, the film thickness is preferably in the range of 10 to 30 μm. Therefore, it is preferable to adjust the supply amount of the insulating resin coating material so that the film thickness after drying is within the above range.

Step (d): As shown in FIG. 3D, the resin sealing member is formed so as to cover at least the second sealing layer 4b. The resin sealing member is preferably formed so as to cover the entire surface of the semiconductor element and the substrate including the second sealing layer 4b. According to the manufacturing method of the present embodiment, since the wire is sealed prior to the formation of the resin sealing member, problems such as wire flow do not occur. The method for forming the resin sealing member is not particularly limited, and a technique well known in the art can be applied.
In one embodiment, the resin sealing member is formed by transfer molding using a curable composition containing the epoxy resin and the phenol resin described above in a mold having a predetermined shape. be able to. Further, the thickness of the resin sealing member is not particularly limited, but since the second sealing layer ensures the insulating property, the resin sealing member can be designed to be thin. In one embodiment, the film thickness of the semiconductor device obtained after forming the resin sealing member can be preferably 1.5 mm or less, more preferably 1.1 mm or less.

In one embodiment, the method for manufacturing a semiconductor device includes a step of electrically connecting a substrate and a semiconductor element arranged on the substrate by a wire, and a liquid encapsulant in a space below the apex of the wire. The step of forming the first sealing layer by supplying and then curing the liquid sealing material, and supplying the insulating resin coating material to the upper part of the first sealing layer via the wire, It then has a step of forming a second sealing layer by drying. In another embodiment, the semiconductor device manufacturing method forms a resin sealing member so as to cover at least the second sealing layer after the step of forming the second sealing layer in the manufacturing method of the above embodiment. Further has a step of

Hereinafter, embodiments of the present invention will be described with reference to examples, but the present invention is not limited to the following examples, and it goes without saying that embodiments with various modifications are also included.

1. 1. Preparation of liquid encapsulant (Preparation Example 1)
The following materials were blended and kneaded and dispersed with a three-roll and vacuum raker to prepare a liquid encapsulant.
Epoxy resin 1: p- (2,3-epoxypropoxy) -N, N-bis (2,3-epoxypropyl) aniline (manufactured by ADEKA Co., Ltd., trade name "EP-3950S", total chlorine content 1500 ppm or less) 60 parts Epoxy resin 2: Bisphenol F type epoxy resin (manufactured by Nippon Steel & Sumikin Chemical Co., Ltd., trade name "YDF-8170C") 20 parts Epoxy resin 3: 1,6-hexanediol diglycidyl ether (Sakamoto Pharmaceutical Co., Ltd., product) Name "SR-16HL") 20 parts Hardener: Diethyltoluenediamine (manufactured by Mitsubishi Chemical Co., Ltd., product name "jER Cure W") 42 parts Ion trapping agent: Bismus-based ion trapping agent (manufactured by Toa Synthetic Co., Ltd., product name) "IXE-500") 3 parts Solvent: Butyl carbitol acetate 57 parts Inorganic filler 1: Spherical molten silica surface-treated with a silane coupling agent (manufactured by Admatex Co., Ltd., trade name "SE5050-SEJ", volume average Particle size 1.5 μm) 707 parts Inorganic filler 2: Spherical molten silica surface-treated with a silane coupling agent (manufactured by Admatex Co., Ltd., trade name “SE2050-SEJ”, volume average particle size 0.5 μm) 235 parts

With respect to the liquid encapsulant prepared as described above, the viscosities at 25 ° C. and a shear rate of 10 ^-1 and the viscosities at 75 ° C. and a shear rate of 5 s ^-1 were measured, respectively. Further, the viscosity at 75 ° C. and a shear rate of 50s- ¹ was measured, and the thixotropy coefficient at 75 ° C. was determined. These results are shown below.
25 ° C. Viscosity: 20 (Pa · s) (shear velocity 10s ^-1 )
75 ° C. Viscosity: 2.0 (Pa · s) (shear velocity 5s ^-1 )
Thixotropy coefficient at 75 ° C: 1.7 (shear velocity 5s ^-1 / 50s ^-1 value)
The viscosity measurement at 25 ° C. was carried out using an E-type viscometer (VISCONIC EHD type manufactured by Tokyo Keiki Co., Ltd.). Further, the viscosity measurement at 75 ° C. was carried out using a rheometer (trade name "AR2000" of TA Instruments).

In addition, the amount of chloride ions (ppm) of the prepared liquid encapsulant was measured. The measurement was carried out by ion chromatography at 121 ° C. for 20 hours, and the measurement was carried out using a sodium carbonate solution as an eluent. As a result of the measurement, the amount of chlorine ions in the liquid encapsulant was 10 ppm.

2. 2. Preparation of Insulating Resin Coated Material (Preparation Example 2)
<Preparation of insulating resin coating material (P-1)>
(1) Synthesis example of heat-resistant resin (B) In a 5-liter four-necked flask equipped with a thermometer, agitator, a nitrogen introduction pipe, and a cooling pipe with an oil-water separator, 2,2-bis [ 650.90 g (1.59 mol) of 4- (4-aminophenoxy) phenyl] propane (hereinafter referred to as BAPP), and 1,3-bis (3-aminopropyl) tetramethyldisiloxane (hereinafter BY16-). 43.80 g (0.18 mol) of 871 (manufactured by Toray Dow Corning Co., Ltd.) was added, and 3609.86 g of N-methyl-2-pyrrolidone (hereinafter referred to as NMP) was further added and dissolved. Next, 384.36 g (1.83 mol) of trimellitic anhydride chloride (hereinafter referred to as TAC) was added while cooling the solution so that the temperature did not exceed 20 ° C.
After stirring at room temperature for 1 hour, while cooling so as not to exceed 20 ° C., 215.90 g (2.14 mol) of triethylamine (hereinafter referred to as TEA) was added, and then the mixture was reacted at room temperature for 1 hour to form a polyamic acid. Manufactured varnish. The obtained polyamic acid varnish was further dehydrated at 180 ° C. for 6 hours to produce a polyamide-imide resin varnish. The precipitate obtained by pouring the varnish of the polyamide-imide resin into water was separated, pulverized, and dried to obtain a polyamide-imide resin powder (PAI-1). The Mw of the obtained polyamide-imide resin (PAI-1) was 77,000.

(2) Example of synthesis of heat-resistant resin (C) 69.72 g of BAPP (BAPP) in a 1-liter four-necked flask equipped with a thermometer, a stirrer, a nitrogen introduction pipe, and a cooling pipe with an oil-water separator under a nitrogen stream. 170.1 mmol) and BY16-871 were added in an amount of 4.69 g (18.9 mmol), and NMP was added in an amount of 693.52 g to dissolve the mixture. Next, while cooling the solution so as not to exceed 20 ° C., 25.05 g (119.0 mmol) of TAC and 3,4,3', 4'-benzophenonetetracarboxylic dianhydride (hereinafter referred to as BTDA) were added. 25.47 g (79.1 mmol) was added.
After stirring at room temperature for 1 hour, 14.42 g (142.8 mmol) of TEA was added while cooling so as not to exceed 20 ° C., and then the reaction was carried out at room temperature for 1 hour to prepare a polyamic acid varnish. The obtained polyamic acid varnish was further dehydrated at 180 ° C. for 6 hours to produce a polyimide resin varnish. The precipitate obtained by pouring the varnish of the polyimide resin into water was separated, pulverized, and dried to obtain a polyimide resin powder (PAIF-1). The Mw of the obtained polyimide resin (PAIF-1) was 42000.

(3) Preparation of Insulating Resin Coated Material γ as the first polar solvent (A1) in a 0.5 liter four-necked flask equipped with a thermometer, agitator, nitrogen introduction tube and cooling tube under a nitrogen stream. 92.4 g of −butyrolactone (hereinafter referred to as γ-BL), 39.6 g of triethylene glycol dimethyl ether (hereinafter referred to as DMTG) as the second polar solvent (A2), and heat-resistant resin (B) first. Add 30.8 g of the synthesized polyamideimide resin powder (PAI-1) and 13.2 g of the polyimide resin powder (PAIF-1) previously synthesized as the heat-resistant resin (C), and raise the temperature to 180 ° C. with stirring. It was warm. After stirring at 180 ° C. for 2 hours, stop heating, allow to cool while stirring, add 16.8 g of γ-BL and 7.2 g of DMTG at 60 ° C., stir for 1 hour, cool, and then yellow composition. Got It was filled in a filter KST-47 (manufactured by Advantech Co., Ltd.), a silicone rubber piston was inserted, and pressure filtration was performed at a pressure of 3.0 kg / cm ² to obtain an insulating resin coating material (P-1). ..

(Preparation Example 3)
<Preparation of insulating resin coating material (P-2) containing inorganic filler>
In the same manner as in Preparation Example 2 (1), after obtaining PAI-1, 5 wt% of AEROSIL200 manufactured by Nippon Aerosil Co., Ltd. was added to prepare an insulating resin coating material for Comparative Example.
Specifically, in a 0.5 liter four-necked flask equipped with a thermometer, a stirrer, a nitrogen introduction tube and a cooling tube, γ-BL was added as the first polar solvent (A1) under a nitrogen stream. 4 g, 39.6 g of triethylene glycol dimethyl ether (hereinafter referred to as DMTG) as the second polar solvent (A2), and the previously synthesized polyamide-imide resin powder (PAI-1) as the heat-resistant resin (B) 30. 8 g and 9.8 g of Aerodil 200 were added, and the temperature was raised to 180 ° C. with stirring. After stirring at 180 ° C. for 2 hours, stop heating, allow to cool while stirring, add 16.8 g of γ-BL and 7.2 g of DMTG at 60 ° C., stir for 1 hour, cool, and then yellow composition. Got Fill the filter KST-47 (manufactured by Advantech Co., Ltd.), insert a silicone rubber piston, pressurize and filter at a pressure of 3.0 kg / cm ² , and perform an insulating resin coating material (P-) for comparative examples. 2) was obtained.

3. 3. Manufacturing of Semiconductor Devices (Example 1)
A semiconductor element was mounted on a glass epoxy substrate with solder, and a structure was prepared in which the semiconductor element mounted on the substrate and the substrate were electrically connected by a gold wire. 4 × 20 gold wire bonds (80 in total) were formed on the four sides of the semiconductor element. The height from the substrate to the apex of the wire was 0.9 mm.
Next, in the space below the apex of the wire of the above structure, a jet dispenser device (device name "S2-910" manufactured by Nordson Advanced Technology Co., Ltd.) was used to seal the liquid obtained in Preparation Example 1. The material was supplied. Next, the supplied liquid sealing material was cured by heating at 175 ° C. for 2 hours to form a first sealing layer (wire sealing layer).
The insulating resin coating material obtained in Preparation Example 2 was supplied onto the first sealing layer using a dispenser device (device name "SDP500" manufactured by Sanei Tech Co., Ltd.) via a wire. Next, a second sealing layer (insulation protective layer) having a film thickness of 12 μm is formed by drying the coating film of the coating material under temperature conditions of 100 ° C. for 30 minutes and further at 200 ° C. for 1 hour. did.

(Comparative Example 1)
In the same manner as in the first embodiment, a structure in which the semiconductor elements mounted on the substrate are electrically connected by wires was prepared. Next, the insulating resin coating material obtained in Preparation Example 2 was supplied only to the upper part of the wire of the structure by using a dispenser device (device name “SDP500” manufactured by Sanei Tech Co., Ltd.). As for the lower part of the wire, the wire became an obstacle and the insulating resin coating material could not be filled well. Then, the coating film was dried under the temperature conditions of 100 ° C. for 30 minutes and 200 ° C. for 1 hour to form a sealing layer (insulation protective layer). The supply amount of the insulating resin coating material was adjusted so that the dry film thickness of the sealing layer located on the upper part of the wire was 12 μm, which was the same as in Example 1.

(Comparative Example 2)
In the same manner as in the first embodiment, a structure in which the semiconductor elements mounted on the substrate are electrically connected by wires was prepared. Next, the liquid encapsulant obtained in Preparation Example 1 was supplied to the lower and upper parts of the wire of the above structure by using a jet dispenser device (device name "S2-910" manufactured by Nordson Advanced Technology Co., Ltd.). Next, a sealing layer (wire sealing layer) was formed by curing the coating film under a temperature condition of 175 ° C. for 2 hours. The film thickness of the sealing layer located above the wire was determined in Example 1. The supply amount of the liquid encapsulant was adjusted so as to be 12 μm, which is the same as the above.

(Comparative Example 3)
In the same manner as in Example 1, a structure electrically connected by a wire of a semiconductor element mounted on a substrate was prepared. Next, in the same manner as in Example 1, after forming a first sealing layer under the wire of the structure, the first sealing layer was obtained in Preparation Example 3 via a wire on the first sealing layer. An insulating resin coating material containing an inorganic filler was supplied. The supply amount of the insulating resin coating material containing the inorganic filler was adjusted so that the dry film thickness of the sealing layer located on the upper part of the wire was 12 μm, which was the same as in Example 1.

4. Evaluation of semiconductor devices <Reliability of semiconductor devices>
With respect to the semiconductor devices obtained in Example 1 and Comparative Examples 1 to 3, the presence or absence of voids in the sealing layer with respect to the wire was judged from ultrasonic microscope measurement, and the reliability of the device was evaluated.
The ultrasonic microscope measurement was carried out by using the device name "D9000" manufactured by SONOSCAN. If the presence of voids in the semiconductor device could not be confirmed by ultrasonic microscopy, the reliability was judged to be good. On the other hand, if the presence of voids could be confirmed by ultrasonic microscopic measurement, it was judged that the reliability was poor. The results are shown in Table 1.

<Dielectric breakdown voltage>
For the semiconductor devices obtained in Example 1 and Comparative Examples 1 to 3, measurement samples were prepared as follows in order to evaluate the dielectric breakdown voltage of the sealing layer formed on the upper part of the wire.
As a measurement sample 1 corresponding to Example 1 (Comparative Example 1), the insulating resin coating material P-1 obtained in Preparation Example 2 was applied on an aluminum substrate with an applicator. Then, it was heated in an oven at 100 ° C. for 30 minutes and further at 200 ° C. for 1 hour to obtain a dry coating film having a film thickness of 10 μm.
As a measurement sample 2 for Comparative Example 2, the liquid encapsulant obtained in Preparation Example 1 was applied on an aluminum substrate with an applicator. Then, the coating film was heat-cured at 175 ° C. for 2 hours to obtain a cured film having a film thickness of 10 μm.
As a measurement sample 3 with respect to Comparative Example 3, an insulating resin coating material P-2 containing the inorganic filler obtained in Preparation Example 3 was applied on an aluminum substrate with an applicator. Then, it was heated in an oven at 100 ° C. for 30 minutes and further at 200 ° C. for 1 hour to obtain a dry coating film having a film thickness of 10 μm.
The measurement samples 1 to 3 prepared as described above were sandwiched between a pair of electrodes, and the dielectric breakdown voltage value was measured. The measurement was carried out in oil with reference to JIS C2110 under the conditions that the step-up speed was 0.5 kV / sec, the measurement temperature was room temperature, and the electrode shape was a sphere having a diameter of 20 mm. The results are shown in Table 1.

<ESD resistance>
For the semiconductor devices obtained in Example 1 and Comparative Examples 1 to 3, the ESD resistance was evaluated from the value of the breakdown voltage of the dry coating film (cured film) separately measured, instead of actually measuring the ESD resistance. For example, the breakdown voltage of the measurement sample 1 produced earlier is 230 kV / mm, which is synonymous with 230 V / μm. Therefore, if the film thickness of the sealing layer (film) obtained by film formation is 10 μm, the sealing layer (film) has an insulating property of 2300 V (2.3 kV). Usually, if the sealing layer (membrane) can maintain the insulating property against a voltage exceeding 2 kV, it is possible to obtain sufficient ESD resistance in the semiconductor device.
In general, increasing the film thickness can increase the insulating property, thereby increasing the ESD resistance. For example, when the material is applied so as to obtain a film thickness of 100 μm or more, it becomes easy to ensure the insulating property. However, it is difficult to uniformly apply the insulating coating material so that a film thickness of 100 μm can be obtained in the first place. It is also not preferable in that it goes against the market trend in which thin semiconductor devices are required. Therefore, as described below, ESD resistance was evaluated from the insulation property calculated from the measured values of the dielectric breakdown voltage of the measurement samples 1 to 3 having a film thickness of 10 μm, using 2 kV as a reference value. The results are shown in Table 1. (ESD evaluation criteria)
Good: Insulation is 2 kV or more.
Defective: Insulation is less than 2 kV.

（注記）
実施例１及び比較例１の絶縁破壊電圧及びＥＳＤ耐性は、測定サンプル１に対する測定値及び評価結果に対応する。比較例２及び３の絶縁破壊電圧及びＥＳＤ耐性の評価は、測定サンプル２及び３に対する測定値及び評価結果に対応する。
ＥＳＤ耐性における絶縁性は、膜厚１０μｍの測定サンプル１〜３の絶縁破壊電圧の測定値から算出される値である。

(Note)
The breakdown voltage and ESD resistance of Example 1 and Comparative Example 1 correspond to the measured values and evaluation results for the measurement sample 1. The evaluation of the dielectric breakdown voltage and ESD resistance of Comparative Examples 2 and 3 corresponds to the measured values and the evaluation results for the measurement samples 2 and 3.
The insulation property in the ESD resistance is a value calculated from the measured values of the dielectric breakdown voltage of the measurement samples 1 to 3 having a film thickness of 10 μm.

As is clear from the comparison between Example 1 and Comparative Examples 1 to 3, according to the embodiment of the present invention (Example 1), the generation of voids is suppressed and a high dielectric breakdown voltage can be obtained. Therefore, according to the present invention, it is possible to provide a thin semiconductor device having excellent insulation and ESD resistance and excellent reliability.

1 Substrate 2 Semiconductor element 3 Wire 3a Wire apex 4a First sealing layer 4b Second sealing layer 5 Resin sealing member h Wire height from the substrate

Claims (20)

A substrate, a semiconductor element arranged on the substrate, a wire for electrically connecting the substrate and the semiconductor element, and a first sealing layer for sealing a space below the apex of the wire. , A semiconductor device having a second sealing layer provided on top of the first sealing layer via the wire.
The first sealing layer is made of a cured film of a liquid sealing material.
A semiconductor device in which the second sealing layer is a dry coating film of an insulating resin coating material. The semiconductor device according to claim 1, further comprising a resin sealing member provided so as to cover at least the second sealing layer. The semiconductor device according to claim 1 or 2, wherein the insulation breakdown voltage of the dry coating film of the insulating resin coating material is 150 kV / mm or more. The semiconductor device according to any one of claims 1 to 3, wherein the insulating resin coating material contains a resin filler having an average particle diameter of 0.1 to 5.0 μm. The semiconductor device according to any one of claims 1 to 4, wherein the insulating resin coating material has a viscosity of 30 to 500 Pa · s at 25 ° C. The semiconductor device according to any one of claims 1 to 5, wherein the insulating resin coating material has a thixotropy coefficient of 2.0 to 10.0 at 25 ° C. The semiconductor device according to any one of claims 1 to 6, wherein the insulating resin coating material contains at least one insulating resin selected from the group consisting of polyamide, polyamide-imide, and polyimide. The semiconductor device according to any one of claims 1 to 7, wherein the film thickness of the second sealing layer is 100 μm or less. The semiconductor device according to claim 8, wherein the film thickness of the second sealing layer is 50 μm or less. The semiconductor device according to any one of claims 7 to 9, wherein the Tg of the insulating resin is 150 ° C. or higher. The liquid encapsulant contains a thermosetting resin component and an inorganic filler, and the viscosity (Pa · s) measured under the conditions of 75 ° C. and a shear rate of 5s ^-1 is defined as viscosity A, and shearing is performed at 75 ° C. When the viscosity (Pa · s) measured under the condition of speed 50s ^-1 is viscosity B, the thixotropy coefficient at 75 ° C. obtained as the value of viscosity A / viscosity B is 0.1 to 2.5. , The semiconductor device according to any one of claims 1 to 10. The semiconductor device according to any one of claims 1 to 11, wherein the amount of chlorine ions in the liquid encapsulant is 100 ppm or less. The maximum particle size of the inorganic filler in the liquid encapsulant is 75 μm or less. The semiconductor device according to any one of claims 11 or 12. The semiconductor device according to any one of claims 1 to 13, wherein the viscosity of the liquid encapsulant measured under the conditions of 75 ° C. and a shear rate of 5s- ¹ is 3.0 Pa · s or less. The semiconductor device according to any one of claims 1 to 14, wherein the viscosity of the liquid encapsulant measured under the conditions of 25 ° C. and a shear rate of 10 s- ¹ is 30 Pa · s or less. The semiconductor device according to any one of claims 11 to 15, wherein the content of the inorganic filler is 50% by mass or more based on the total mass of the liquid encapsulant. The semiconductor device according to any one of claims 11 to 16, wherein the thermosetting resin component in the liquid encapsulant contains an aromatic epoxy resin and an aliphatic epoxy resin. The aromatic epoxy resin contains at least one selected from the group consisting of a liquid bisphenol type epoxy resin and a liquid glycidylamine type epoxy resin, and the aliphatic epoxy resin contains a linear aliphatic epoxy resin. The semiconductor device according to claim 17. The semiconductor device according to any one of claims 1 to 18, which is used for a fingerprint authentication sensor. A substrate, a semiconductor element arranged on the substrate, a wire for electrically connecting the substrate and the semiconductor element, and a first sealing layer for sealing a space below the apex of the wire. , A method for manufacturing a semiconductor device having a second sealing layer provided on the upper part of the first sealing layer via the wire.
A process of electrically connecting a substrate and a semiconductor element arranged on the substrate with a wire,
A step of supplying a liquid sealing material to a space below the apex of the wire to form a first sealing layer, and
A method for manufacturing a semiconductor device, comprising a step of supplying an insulating resin coating material to an upper portion of the first sealing layer via the wire to form a second sealing layer.

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