JP7091618B2 - Capacitance type sensor encapsulation resin composition and capacitance type sensor - Google Patents

Description

The present invention relates to a resin composition for encapsulating a capacitance type sensor and a capacitance type sensor.

Various techniques are being studied for capacitive sensors. For example, in Patent Document 1, a semiconductor fingerprint sensor that detects fingerprint information by a capacitance method is studied.
Patent Document 1 describes a fingerprint reading sensor in which a plurality of sensor chips are arranged in an array on a substrate such as silicon via an interlayer film, and the upper surface thereof is overcoated with an insulating film (sealing film). ing.

Japanese Unexamined Patent Publication No. 2004-234245

The technical level required for various characteristics of capacitive sensors is becoming higher and higher. The present inventor has found the following problems with respect to the conventional capacitive sensor.
On the surface of the sealing film provided in the conventional capacitance type sensor, a fine step called a die mark may occur between the region where the sensor chip is arranged and the region where the sensor chip is not arranged. Then, the present inventors have room for improvement in that when the above-mentioned fine step is formed in the conventional capacitance type sensor, the appearance defect of the sensor is suppressed and the yield is sufficiently improved. I found that there is.

Therefore, the present invention provides a resin composition capable of producing a capacitance type sensor having no appearance defect with good yield and a capacitance type sensor having excellent sensitivity.

The present inventors have made extensive studies to achieve the above-mentioned problems. As a result, it was found that the scale of the shrinkage rate of the test piece made of the cured product of the resin composition obtained by curing under the predetermined conditions devised by the present inventors is effective as such a design guideline, and the present invention. Reached.

（式（１）中、Ａｒ ^１ はフェニレン基またはナフチレン基を表し、Ａｒ ^１ がナフチレン基の場合、グリシジルエーテル基はα位、β位のいずれに結合していてもよい。Ａｒ ^２ はフェニレン基、ビフェニレン基またはナフチレン基のうちのいずれか１つの基を表す。Ｒ _ａ およびＲ _ｂ は、それぞれ独立に炭素数１～１０の炭化水素基を表す。ｇは０～５の整数であり、ｈは０～８の整数である。ｎ ^３ は重合度を表し、その平均値は１～３である。）

（式（２）中、複数存在するＲ _ｃ は、それぞれ独立に水素原子または炭素数１～４の炭化水素基を表す。ｎ ^５ は重合度を表し、その平均値は０～４である。）

（式（３）中、複数存在するＲ _ｄ およびＲ _ｅ は、それぞれ独立に水素原子又は炭素数１～４の炭化水素基を表す。ｎ ^６ は重合度を表し、その平均値は０～４である。）
According to the present invention
A resin composition for encapsulating a capacitive sensor, which is used for forming a sealing film in a capacitive sensor.
Epoxy resin and
Hardener and
Filler and
Including
The epoxy resin includes an epoxy resin containing a structural unit represented by the following formula (1), an epoxy resin containing a structural unit represented by the following formula (2), and a structural unit represented by the following formula (3). Containing at least one selected from the group consisting of epoxy resins containing
The curing agent is a phenol resin,
The hydroxyl group equivalent of the phenol resin is 70 g / eq or more and 400 g / eq or less.
When the number of epoxy groups of the epoxy resin is EP and the number of hydroxyl groups of the phenol resin is OH, the equivalent ratio determined by (EP) / (OH) is 0.7 or more and 1.50 or less.
The filler comprises one or more selected from silica, alumina, titanium oxide and barium titanate.
The content of the filler with respect to the total solid content of the capacitance type sensor encapsulating resin composition is 50% by mass or more and 90% by mass or less.
The glass transition temperature of the cured product of the capacitive sensor encapsulating resin composition is 159 ° C. or higher and 250 ° C. or lower.
Provided is a resin composition for encapsulating a capacitive sensor having a shrinkage ratio of less than 0.19% measured under the following condition 1.
(Condition 1: Condition 1:
Using a transfer molding machine, the resin composition for encapsulating the capacitive sensor is injected and molded into the mold cavity under the conditions of a mold temperature of 175 ° C., a molding pressure of 9.8 MPa, and a curing time of 2 minutes. Make a disk-shaped test piece.
Then, the obtained test piece is heat-treated at 175 ° C. for 4 hours and then cooled to 25 ° C. Here, the inner diameter of the mold cavity at 175 ° C. and the outer diameter of the test piece at 25 ° C. are measured.
Then, the shrinkage rate S (%) is calculated based on the following formula.
S = {(inner diameter dimension of mold cavity at 175 ° C.)-(outer diameter dimension of test piece at 25 ° C.)} / (inner diameter dimension of mold cavity at 175 ° C.) × 100 )

(In the formula (1), Ar ¹ represents a phenylene group or a naphthylene group, and when Ar ¹ is a naphthylene group, the glycidyl ether group may be bonded to either the α-position or the β-position. Ar ² is a phenylene group. , Any one of a biphenylene group or a naphthylene group. R _a and R _b each independently represent a hydrocarbon group having 1 to 10 carbon atoms. G is an integer of 0 to 5 and h. Is an integer of 0 to 8. n ³ represents the degree of polymerization, and the average value thereof is 1 to 3.)

(In the formula (2), a plurality of R _cs independently represent a hydrogen atom or a hydrocarbon group having 1 to 4 carbon atoms. N ⁵ represents a degree of polymerization, and the average value thereof is 0 to 4. )

(In the formula (3), a plurality of R _d and _Re each independently represent a hydrogen atom or a hydrocarbon group having 1 to 4 carbon atoms. N ⁶ represents the degree of polymerization, and the average value thereof is 0 to 4. Is.)

Further, according to the present invention, the substrate and
The detection electrode provided on the substrate and
A sealing film that seals the detection electrode and is made of a cured product of the resin composition for encapsulating a capacitance type sensor.
Capacitive sensors are provided.

INDUSTRIAL APPLICABILITY According to the present invention, it is possible to provide a resin composition capable of producing a capacitance type sensor having no appearance defect with good yield and a capacitance type sensor having excellent sensitivity.

It is sectional drawing which shows typically the capacitance type sensor which concerns on this embodiment.

Hereinafter, embodiments will be described with reference to the drawings. In all the drawings, similar components are designated by the same reference numerals, and the description thereof will be omitted as appropriate.

<Resin composition for encapsulating capacitance type sensor>
The resin composition for encapsulating a capacitive sensor according to the present embodiment (hereinafter, also referred to as the present resin composition) is used for forming a sealing film in a capacitive sensor. The present resin composition contains an epoxy resin, a curing agent, and a filler, and the shrinkage rate of the test piece made of the resin composition obtained under the following condition 1 is less than 0.19%. It is controlled to be. By doing so, it is possible to suppress the formation of a fine step on the surface of the sealing film provided in the capacitance type sensor. As a result, it is possible to suppress the occurrence of appearance defects called die marks on the surface of the capacitance type sensor, and as a result, it is possible to manufacture a capacitance type sensor without appearance defects with good yield.
(Condition 1: The cured product obtained by heat-treating the capacitive sensor encapsulating resin composition at 175 ° C. for 2 minutes and then heat-treating at 175 ° C. for 4 hours is the test piece. ()

The shrinkage rate of the test piece made of the present resin composition can be controlled by appropriately adjusting the type and content of each component contained in the resin composition, the particle size distribution of the present resin composition, and the like. Is. In the present embodiment, for example, the type and content of a filler, a curing agent, a coupling agent, and the like may be adjusted. More specifically, for example, adjusting the content of the filler, adjusting the average particle size of the filler, using a polyfunctional resin material, adjusting the equivalent ratio of the epoxy resin and the curing agent, and the like. By devising the method, it is possible to control the value of the shrinkage rate of the test piece made of the present resin composition.

Here, the upper limit of the shrinkage rate of the test piece made of the present resin composition is less than 0.19%, preferably 0.17% or less, and more preferably 0.165% or less. Yes, more preferably 0.16% or less.
On the other hand, the lower limit of the shrinkage rate of the test piece made of the present resin composition is not particularly limited, and may be 0% or more, 0.01% or more, or may be. It may be 0.1% or more.

Further, in the present embodiment, the test piece made of the capacitive sensor encapsulating resin composition obtained under the following condition 2 is measured at break elongation by a method according to JIS K7161 under a temperature condition of 150 ° C. However, it is preferably 2 mm or more, more preferably 2.4 mm or more, and further preferably 4 mm or more. By doing so, while suppressing the occurrence of a fine step on the surface of the sealing film provided in the capacitance type sensor, in the region such as the bonding interface between the sealing film and the electrode in the capacitance type sensor. It is also possible to suppress the occurrence of cracks. On the other hand, the upper limit of the elongation at break described above is not particularly limited, and may be, for example, 100 mm or less, or 70 mm or less.
(Condition 2: The capacitance type sensor encapsulation resin composition is heat-treated at 175 ° C. for 2 minutes and then heat-treated at 175 ° C. for 4 hours, and is in accordance with JIS K7161. The cured product formed so as to have a dumbbell shape is used as the test piece.)

The elongation at break of the test piece made of the present resin composition can be controlled by appropriately adjusting the type and content of each component contained in the resin composition, the particle size distribution of the present resin composition, and the like. Is. In the present embodiment, for example, the type and content of a filler, a curing agent, a coupling agent, and the like may be adjusted. More specifically, for example, the balance between the content of the filler and the content of the resin material is adjusted, the resin component having a long distance between the cross-linking points is contained, and the glass transition temperature is within a specific range. It is possible to control the value of the elongation at break of the test piece made of the present resin composition by taking measures such as setting the components.

The gel time measured under the following condition 3 of the present resin composition is preferably 30 seconds or more and 90 seconds or less, more preferably 35 seconds or more and 85 seconds or less, and further preferably 40 seconds or more and 80 seconds or less. Less than a second. By doing so, it becomes possible to suppress the generation of flow marks on the surface of the sealing film provided in the capacitance type sensor, and as a result, the yield of the capacitance type sensor can be further improved. can.
(Condition 3: When the maximum torque value when the curing torque of the resin composition for encapsulating the capacitance type sensor is measured over time at a mold temperature of 175 ° C. using a curast meter is T. The time required from the start of the measurement until the value of the curing torque reaches 0.1 T is defined as the gel time.)

The value of the gel time according to the present resin composition can be controlled by appropriately adjusting the type and content of each component contained in the resin composition. In the present embodiment, for example, the value of the gel time related to the present resin composition can be controlled by taking measures such as reducing the content of the curing accelerator with respect to the total amount of the resin composition.

Hereinafter, the present resin composition will be described in detail.

(Epoxy resin)
As the epoxy resin, a monomer, an oligomer, or a polymer having two or more epoxy groups in one molecule can be used in general, and the molecular weight and molecular structure thereof are not particularly limited.
In the present embodiment, the epoxy resin includes, for example, a biphenyl type epoxy resin; a bisphenol type epoxy resin such as a bisphenol A type epoxy resin, a bisphenol F type epoxy resin, and a tetramethyl bisphenol F type epoxy resin; a stillben type epoxy resin; a phenol novolak. Novolak type epoxy resin such as type epoxy resin, cresol novolak type epoxy resin; polyfunctional epoxy resin such as triphenylmethane type epoxy resin, alkyl modified triphenylmethane type epoxy resin; phenol aralkyl type epoxy resin having phenylene skeleton, biphenylene skeleton Aralkyl type epoxy resin such as phenol aralkyl type epoxy resin; naphthol type epoxy resin such as dihydroxynaphthalene type epoxy resin and epoxy resin obtained by glycidyl etherification of dihydroxynaphthalene dimer; triglycidyl isocyanurate, monoallyldi Examples thereof include triazine nuclei-containing epoxy resins such as glycidyl isocyanurate; and bridged cyclic hydrocarbon compound-modified phenol-type epoxy resins such as dicyclopentadiene-modified phenol-type epoxy resins. It may be used together.
Of these, from the viewpoint of improving the balance between moisture resistance reliability and moldability, phenol aralkyl types such as bisphenol type epoxy resin, novolak type epoxy resin, biphenyl type epoxy resin (biphenol type epoxy resin), and biphenyl aralkyl type epoxy resin are used. It is more preferable to contain at least one of the epoxy resin and the triphenylmethane type epoxy resin, and it is particularly preferable to contain at least one of the biphenyl type epoxy resin and the phenol aralkyl type epoxy resin.

The epoxy resin includes an epoxy resin containing a structural unit represented by the following formula (1), an epoxy resin containing a structural unit represented by the following formula (2), and a structural unit represented by the following formula (3). It is preferable to contain at least one selected from the group consisting of the containing epoxy resin.

（式（１）中、Ａｒ^１はフェニレン基またはナフチレン基を表し、Ａｒ^１がナフチレン基の場合、グリシジルエーテル基はα位、β位のいずれに結合していてもよい。Ａｒ^２はフェニレン基、ビフェニレン基またはナフチレン基のうちのいずれか１つの基を表す。Ｒ_ａおよびＲ_ｂは、それぞれ独立に炭素数１～１０の炭化水素基を表す。ｇは０～５の整数であり、ｈは０～８の整数である。ｎ^３は重合度を表し、その平均値は１～３である。）

(In the formula (1), Ar ¹ represents a phenylene group or a naphthylene group, and when Ar ¹ is a naphthylene group, the glycidyl ether group may be bonded to either the α-position or the β-position. Ar ² is a phenylene group. , Any one of a biphenylene group or a naphthylene group. R _a and R _b each independently represent a hydrocarbon group having 1 to 10 carbon atoms. G is an integer of 0 to 5 and h. Is an integer of 0 to 8. n ³ represents the degree of polymerization, and the average value thereof is 1 to 3.)

（式（２）中、複数存在するＲ_ｃは、それぞれ独立に水素原子または炭素数１～４の炭化水素基を表す。ｎ^５は重合度を表し、その平均値は０～４である。）

(In the formula (2), a plurality of R _cs independently represent a hydrogen atom or a hydrocarbon group having 1 to 4 carbon atoms. N ⁵ represents a degree of polymerization, and the average value thereof is 0 to 4. )

（式（３）中、複数存在するＲ_ｄおよびＲ_ｅは、それぞれ独立に水素原子又は炭素数１～４の炭化水素基を表す。ｎ^６は重合度を表し、その平均値は０～４である。）

(In the formula (3), a plurality of R _d and _Re each independently represent a hydrogen atom or a hydrocarbon group having 1 to 4 carbon atoms. N ⁶ represents the degree of polymerization, and the average value thereof is 0 to 4. Is.)

The content of the epoxy resin in the present resin composition is preferably 2% by mass or more, more preferably 3% by mass or more, when the total solid content of the present resin composition is 100% by mass. It is particularly preferable that it is 4% by mass or more. By setting the content of the epoxy resin to the above lower limit value or more, sufficient fluidity can be realized at the time of molding, and the filling property and the moldability can be improved.

On the other hand, the content of the epoxy resin in the present resin composition is preferably 30% by mass or less, preferably 20% by mass or less, when the total solid content of the present resin composition is 100% by mass. It is more preferably 10% by mass or less, and particularly preferably 10% by mass or less. By setting the content of the epoxy resin to the above upper limit or less, it is possible to improve the moisture resistance reliability and the reflow resistance of the capacitance type sensor using the cured product of the present resin composition as the sealing film.

The lower limit of the epoxy equivalent of the epoxy resin is, for example, preferably 70 g / eq or more, more preferably 100 g / eq or more, further preferably 120 g / eq or more, and 140 g / eq or more. It is more preferable to have it, and it is particularly preferable that it is 160 g / eq or more. As a result, the distance between the cross-linking points can be increased.
The upper limit of the epoxy equivalent of the epoxy resin may be, for example, 400 g / eq or less, or 300 g / eq or less.

(filler)
The filler according to the present embodiment is not particularly limited as long as it has a relative permittivity (1 MHz) of 4 or more, but for example, silica can be used from the viewpoint of particularly improving the relative permittivity of the cured product of the obtained resin composition. , Alumina, titanium oxide and barium titanate are preferably selected from one or more, and one or more selected from silica, alumina and barium titanate from the viewpoint of suppressing oxidative deterioration of the resin. Is more preferable to use. By using a filler having a high relative permittivity, the sensitivity of the sensor when the capacitance type sensor encapsulating resin composition is used for the fingerprint sensor can be improved.
Further, in the present embodiment, from the viewpoint of providing a technique capable of producing a capacitive sensor having no appearance defect with good yield, it is possible to use two or more kinds of fillers having different average particle diameters ( _D50 ) in combination. preferable.

The lower limit of the content of the filler in the resin composition is preferably 50% by mass or more with respect to the entire solid content of the resin composition when the total solid content of the resin composition is 100% by mass. It is more preferably 60% by mass or more, and particularly preferably 70% by mass or more. By setting the content of the filler to the above lower limit value or more, the dielectric property of the present resin composition can be further improved, and the sensitivity of the capacitance type sensor can be further improved.
On the other hand, the upper limit of the content of the filler in the present resin composition is preferably 90% by mass or less, preferably 89% by mass or less, when the total solid content of the present resin composition is 100% by mass. It is more preferable to have. By setting the content of the filler to the above upper limit value or less, it is possible to more effectively improve the fluidity and the filling property of the present resin composition at the time of molding.

The upper limit of the average particle size _D50 of the filler is, for example, preferably 8 μm or less, more preferably 5 μm or less, further preferably 4 μm or less, and further preferably 3.5 μm or less. preferable. As a result, the filler can be uniformly dispersed in the present resin composition, and the local improvement in the shrinkage rate can be suppressed. In addition, it is possible to reliably suppress the occurrence of gate clogging and the like.
The lower limit of the average particle size _D50 of the filler is, for example, preferably 0.2 μm or more, and more preferably 0.5 μm or more. As a result, it is possible to prevent the filler having an increased specific surface area from aggregating. In addition, the fluidity of the present resin composition can be improved, and the moldability can be improved more effectively.
The average particle size D ₅₀ is measured by measuring the particle size distribution of the particles on a volume basis using a commercially available laser particle size distribution meter (for example, SALD-7000 manufactured by Shimadzu Corporation), and the median diameter (D) thereof. ₅₀ ) can be the average particle size D ₅₀ .

(Hardener)
The present resin composition may contain, for example, a curing agent. The curing agent is not particularly limited as long as it is cured by reacting with an epoxy resin, but for example, a linear aliphatic diamine having 2 to 20 carbon atoms such as ethylenediamine, trimethylenediamine, tetramethylenediamine, and hexamethylenediamine. , Metaphenylenediamine, Paraphenylenediamine, Paraxylenediamine, 4,4'-diaminodiphenylmethane, 4,4'-diaminodiphenylpropane, 4,4'-diaminodiphenyl ether, 4,4'-diaminodiphenylsulfone, 4,4 '-Diaminodicyclohexane, bis (4-aminophenyl) phenylmethane, 1,5-diaminonaphthalene, metaxylenediamine, paraxylenediamine, 1,1-bis (4-aminophenyl) cyclohexane, dicyanodiamide and other amines Resol-type phenolic resin such as aniline-modified resol resin and dimethyl ether resol resin; Novolak-type phenolic resin such as phenol novolac resin, cresol novolak resin, tert-butylphenol novolak resin, nonylphenol novolak resin; triphenylmethane-type phenol resin (triphenylmethane) Polyfunctional phenolic resin (type phenolic resin); Phenolic aralkyl resin containing phenylene skeleton; Phenolic aralkyl resin such as biphenylene skeleton-containing phenol aralkyl type phenol resin (biphenyl aralkyl type phenol resin); Phenolic resin having a ring structure; polyoxystyrene such as polyparaoxystyrene; alicyclic acid anhydrides such as hexahydrophthalic anhydride (HHPA) and methyltetrahydrophthalic anhydride (MTHPA), trimellitic anhydride (TMA), anhydrous. Acid anhydrides and the like containing aromatic acid anhydrides such as pyromellitic acid (PMDA) and benzophenone tetracarboxylic acid (BTDA); polypeptide compounds such as polysulfide, thioester and thioether; isocyanates such as isocyanate prepolymer and blocked isocyanate. Compounds; Examples thereof include organic acids such as carboxylic acid-containing polyester resins. One of these may be used alone, or two or more thereof may be used in combination.

The content of the curing agent in the present resin composition is not particularly limited, but for example, when the total solid content of the present resin composition is 100% by mass, it may be 0.5% by mass or more and 20% by mass or less. It is more preferably 1.5% by mass or more and 20% by mass or less, further preferably 2% by mass or more and 15% by mass or less, and particularly preferably 2% by mass or more and 10% by mass or less.

When the curing agent is a phenol resin, the lower limit of the hydroxyl group equivalent is, for example, preferably 70 g / eq or more, more preferably 80 g / eq or more, still more preferably 90 g / eq or more. , 100 g / eq is more preferred. As a result, the distance between the cross-linking points can be increased.
When the curing agent is a phenol resin, the upper limit of the hydroxyl group equivalent may be, for example, 400 g / eq or less, or 300 g / eq or less.

When the curing agent is a phenol resin, the epoxy resin and the phenol resin are equivalents determined by (EP) / (OH) when the number of epoxy groups of the total epoxy resin is EP and the number of hydroxyl groups of the total phenol resin is OH. The upper limit of the ratio is, for example, preferably 1.50 or less, more preferably 1.40 or less, further preferably 1.30 or less, and even more preferably 1.15 or less. , 1.05 or less is particularly preferable. This makes it possible to form an appropriate crosslinked structure. Therefore, the shrinkage rate can be within the above numerical range.
When the curing agent is a phenol resin, the lower limit of the equivalent ratio determined by (EP) / (OH) may be, for example, 0.7 or more, 0.8 or more, or 0.9 or more. It may be 1.0 or more.

(Coupling agent)
The present resin composition can contain, for example, a coupling agent. Examples of the coupling agent include various silane compounds such as epoxysilane, mercaptosilane, aminosilane, alkylsilane, ureidosilane and vinylsilane, titanium compounds, aluminum chelates, and known coupling agents such as aluminum / zirconium compounds. Can be used.
Examples of these are vinyltrichlorosilane, vinyltrimethoxysilane, vinyltriethoxysilane, vinyltris (β-methoxyethoxy) silane, γ-methacryloxypropyltrimethoxysilane, β- (3,4-epoxycyclohexyl) ethyltrimethoxy. Silane, γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropyltriethoxysilane, γ-glycidoxypropylmethyldimethoxysilane, γ-methacryloxypropylmethyldiethoxysilane, γ-methacryloxypropyltriethoxysilane , Vinyl Triacetoxysilane, γ-mercaptopropyltrimethoxysilane, γ-aminopropyltriethoxysilane, γ-anilinopropyltrimethoxysilane, γ-anilinopropylmethyldimethoxysilane, γ- [bis (β-hydroxyethyl) ] Aminopropyltriethoxysilane, N-β- (aminoethyl) -γ-aminopropyltrimethoxysilane, N-β- (aminoethyl) -γ-aminopropyltriethoxysilane, N-β- (aminoethyl)- γ-Aminopropylmethyldimethoxysilane, N-phenyl-γ-aminopropyltrimethoxysilane, γ- (β-aminoethyl) aminopropyldimethoxymethylsilane, N- (trimethoxysilylpropyl) ethylenediamine, N- (dimethoxymethylsilyl) Isopropyl) ethylenediamine, methyltrimethoxysilane, dimethyldimethoxysilane, methyltriethoxysilane, N-β- (N-vinylbenzylaminoethyl) -γ-aminopropyltrimethoxysilane, γ-chloropropyltrimethoxysilane, hexamethyldisilane , Vinyl Trimethoxysilane, γ-Mercaptopropylmethyldimethoxysilane, 3-Ixionpropyltriethoxysilane, 3-Acryloxypropyltrimethoxysilane, 3-Triethoxysilyl-N- (1,3-dimethyl-butylidene) propylamine Hydrolyzate and other silane coupling agents, isopropyltriisostearoyl titanate, isopropyltris (dioctylpyrophosphate) titanate, isopropyltri (N-aminoethyl-aminoethyl) titanate, tetraoctylbis (ditridecylphosphite) titanate. , Tetra (2,2-diallyloxymethyl-1-butyl) bis (ditridecyl) phosphite titanate, bis (dioctylpa) Irophosphate) oxyacetate titanate, bis (dioctylpyrophosphate) ethylene titanate, isopropyltrioctanoyl titanate, isopropyldimethacrylisostearoyl titanate, isopropyltridodecylbenzenesulfonyl titanate, isopropylisostearoyldiacryl titanate, isopropyltri (dioctylphosphate) titanate , Isopropyltricumylphenyl titanate, tetraisopropylbis (dioctylphosphite) titanate and other titanate-based coupling agents. These may be used individually by 1 type and may be used in combination of 2 or more type.

The content of the coupling agent in the present resin composition is not particularly limited, but is, for example, 0.01% by mass or more and 3% by mass or less when the total solid content of the present resin composition is 100% by mass. Is preferable, and it is particularly preferable that it is 0.1% by mass or more and 2% by mass or less. By setting the content of the coupling agent to the above lower limit value or more, the dispersibility of the filler in the present resin composition can be improved. Further, by setting the content of the coupling agent to the above upper limit value or less, the fluidity of the present resin composition can be improved and the moldability can be improved.

(Other ingredients)
In addition to the above components, the present resin composition has a phosphorus atom such as an organic phosphine, a tetra-substituted phosphonium compound, a phosphobetaine compound, an adduct of a phosphine compound and a quinone compound, or an adduct of a phosphonium compound and a silane compound. Containing compound, or amidin compound such as 1,8-diazabicyclo (5.4.0) undecene-7, imidazole, tertiary amine such as benzyldimethylamine, amidine salt or ammonium which is a quaternary onium salt of the above compound. Curing accelerators such as nitrogen atom-containing compounds typified by salts; Colorants such as carbon black; Natural waxes, synthetic waxes such as stearyl alcohol-modified olefin / maleic acid copolymers, higher fatty acids or metal salts thereof, paraffins, Demolding agent such as polyethylene oxide; polybutadiene compound, acrylonitrile-butadiene copolymer such as acrylonitrile-butadiene rubber, low stress agent such as silicone oil and silicone rubber; ion trapping agent such as hydrotalcite; difficulty of aluminum hydroxide etc. Fuel agent; Various additives such as an antioxidant can be contained.
In addition, tetraphenylphosphonium / bisphenol S salt and tetraphenylphosphonium / 2,3-dihydroxynaphthalene salt can also be contained in the present resin composition as the above-mentioned curing accelerator.

The upper limit of the content of the curing accelerator in the present resin composition is preferably 5.5% by mass or less when the total solid content of the present resin composition is 100% by mass, for example, 5.2. It is more preferably 5% by mass or less, and further preferably 5.0% by mass or less. Thereby, the value of the gel time related to the present resin composition can be set within the above numerical range. Therefore, it is possible to suppress the generation of flow marks on the surface of the capacitance type sensor.
Further, the lower limit of the content of the curing accelerator in the present resin composition may be, for example, 0.1% by mass or more, or 0.5% by mass or more.

The upper limit of the total content (RC) of the resin components in the resin composition may be, for example, 15.0% by mass or less when the content of the filler in the resin composition is 100% by mass. It is more preferably 14.0% by mass or less, and even more preferably 13.0% by mass or less. Thereby, the value of the shrinkage rate of the test piece made of the present resin composition can be kept within the above numerical range. Therefore, it is possible to prevent the appearance defect called a die mark from occurring on the surface of the capacitance type sensor.
Further, the lower limit of the total content (RC) of the resin components in the present resin composition may be, for example, 1% by mass or more when the content of the filler in the resin composition is 100% by mass. It may be mass% or more.
In this embodiment, the resin component indicates the total of the epoxy resin, the curing agent, and the curing accelerator.

The relative permittivity (ε _r ) of the cured product of the present resin composition at 1 MHz is preferably 4 or more, more preferably 5 or more, still more preferably 6 or more, and particularly preferably 6.5 or more. be. When the relative permittivity (ε _r ) is at least the above lower limit value, the dielectric property of the present resin composition can be further improved, and the sensitivity of the capacitance type sensor can be further improved.
The cured product of this resin composition is obtained by, for example, compression molding the high dielectric resin composition using a compression molding machine under the conditions of a mold temperature of 175 ° C., a molding pressure of 9.8 MPa, and a curing time of 300 seconds. can get. This cured product has, for example, a diameter of 50 mm and a thickness of 3 mm.
The relative permittivity (ε _r ) of the cured product can be measured by, for example, Q-METER 4342A manufactured by Yokogawa-HELLETT PACKARD.
The upper limit of the relative permittivity (ε _r ) is not particularly limited, but is, for example, 300 or less.

The dielectric loss tangent (tan δ) of the cured product of the present resin composition at 1 MHz is preferably 0.005 or more, more preferably 0.006 or more, and further preferably 0.007 or more.
When the dielectric loss tangent (tan δ) is at least the above lower limit value, the dielectric property of the present resin composition can be further improved, and the sensitivity of the capacitance type sensor can be further improved.
The cured product of the present resin composition can be obtained by, for example, compression molding the present resin composition using a compression molding machine under the conditions of a mold temperature of 175 ° C., a molding pressure of 9.8 MPa, and a curing time of 300 seconds. .. This cured product has, for example, a diameter of 50 mm and a thickness of 3 mm.
The dielectric loss tangent (tan δ) of the cured product can be measured by, for example, Q-METER 4342A manufactured by Yokogawa-Hewlett-Packard.
The upper limit of the dielectric loss tangent (tan δ) is not particularly limited, but is, for example, 0.07 or less.

The relative permittivity (ε _r ) and the dielectric loss tangent (tan δ) can be controlled by appropriately adjusting the type and blending ratio of each component constituting the present resin composition. In the present embodiment, in particular, appropriate selection of the type and content of the filler is mentioned as a factor for controlling the relative permittivity (ε _r ) and the dielectric loss tangent (tan δ). For example, the more the inorganic filler having a large dielectric constant is used, the more the relative permittivity (ε _r ) and the dielectric loss tangent (tan δ) of the cured product of the present resin composition can be improved.

The flow length of the present resin composition measured by spiral flow measurement is preferably, for example, 30 cm or more and 200 cm or less. This makes it possible to improve the moldability of the present resin composition. For the spiral flow measurement of this resin composition, for example, using a transfer molding machine, a mold for measuring the spiral flow according to EMMI-1-66 has a mold temperature of 175 ° C., an injection pressure of 9.8 MPa, and an injection time of 15. This is performed by injecting the present resin composition under the conditions of seconds and curing time of 120 to 180 seconds, and measuring the flow length.

The glass transition temperature of the cured product of the present resin composition is preferably 100 ° C. or higher, more preferably 120 ° C. or higher, further preferably 140 ° C. or higher, and further preferably 159 ° C. or higher. preferable. This makes it possible to more effectively improve the heat resistance of the capacitance type sensor.
The upper limit of the glass transition temperature may be, for example, 250 ° C. or lower, preferably 200 ° C. or lower, more preferably 180 ° C. or lower, and even more preferably 175 ° C. or lower. This makes it possible to reduce the binding property of the molecular chain after curing of the present resin composition. Therefore, it is possible to suppress the occurrence of cracks due to the load.

The coefficient of linear expansion (CTE1) of the cured product of the present resin composition at a glass transition temperature or lower is preferably 3 ppm / ° C. or higher, and more preferably 6 ppm / ° C. or higher. The coefficient of linear expansion (CTE1) at the glass transition temperature or lower is, for example, preferably 50 ppm / ° C. or lower, more preferably 30 ppm / ° C. or lower, and even more preferably 15 ppm / ° C. or lower. By controlling the CTE 1 in this way, it is possible to more reliably suppress the warp of the capacitance type sensor due to the difference in the linear expansion coefficient between the substrate (for example, a silicon chip) and the sealing film.

The coefficient of linear expansion (CTE2) of the cured product of the present resin composition when the glass transition temperature is exceeded is preferably 10 ppm / ° C. or higher. The coefficient of linear expansion (CTE2) when the glass transition temperature is exceeded is, for example, preferably 100 ppm / ° C. or lower, more preferably 50 ppm / ° C. or lower, and even more preferably 47 ppm / ° C. or lower. By controlling CTE2 in this way, the warp of the capacitance type sensor due to the difference in the linear expansion coefficient between the substrate (for example, silicon chip) and the sealing film can be more reliably suppressed, especially in a high temperature environment. Can be done.

The glass transition temperature and the coefficient of linear expansion (CTE1, CTE2) of the cured product of the present resin composition can be measured, for example, as follows.
The cured product of the present resin composition can be obtained by, for example, compression molding the present resin composition using a compression molding machine under the conditions of a mold temperature of 175 ° C., a molding pressure of 9.8 MPa, and a curing time of 300 seconds. .. This cured product has, for example, a length of 10 mm, a width of 4 mm, and a thickness of 4 mm.
Then, after the obtained cured product was post-cured at 175 ° C. for 4 hours, a thermomechanical analyzer (TMA100 manufactured by Seiko Denshi Kogyo Co., Ltd.) was used to measure the temperature range from 0 ° C. to 320 ° C. and the heating rate. The measurement is performed under the condition of 5 ° C./min. From this measurement result, the glass transition temperature, the linear expansion coefficient (CTE1) below the glass transition temperature, and the linear expansion coefficient (CTE2) when the glass transition temperature is exceeded are calculated.

The flexural modulus of the cured product of the present resin composition at 260 ° C. is, for example, preferably 200 MPa or more, more preferably 250 MPa or more, further preferably 300 MPa or more, and more preferably 400 MPa or more. More preferred. The flexural modulus at 260 ° C. is preferably 1500 MPa or less, for example.
By controlling the flexural modulus at 260 ° C. in this way, it is possible to suppress the deformation of the sealing film especially after the curing step until it is cooled to room temperature, and the subsequent warpage of the capacitance type sensor can be suppressed. Can be suppressed more reliably.
Further, by setting the flexural modulus at 260 ° C. to the above upper limit value or less, stress from the outside and thermal stress are effectively relaxed to improve solder resistance and the like, and the reliability of the capacitance type sensor is improved. It is possible to improve the sex.

The flexural modulus of the cured product of the present resin composition at 260 ° C. can be measured, for example, as follows.
The cured product of the present resin composition can be obtained by, for example, compression molding the present resin composition using a compression molding machine under the conditions of a mold temperature of 175 ° C., a molding pressure of 9.8 MPa, and a curing time of 300 seconds. .. This cured product has, for example, a length of 80 mm, a width of 10 mm, and a thickness of 4 mm.
Next, the obtained cured product is post-cured at 175 ° C. for 4 hours, and then the flexural modulus of the cured product at 260 ° C. is measured according to JIS K 6911.

The linear expansion coefficient (CTE1) and the linear expansion coefficient (CTE2) relating to the cured product of the present resin composition determine the type and content of each component contained in the resin composition, the particle size distribution of the present resin composition, and the like. It is possible to control each by adjusting appropriately. In the present embodiment, for example, by increasing the content of the filler and improving the cross-linking density of the resin component used, the linear expansion coefficient (CTE1) of the cured product of the present resin composition is obtained. And the value of the coefficient of linear expansion (CTE2) can be controlled.

<Manufacturing method of resin composition for encapsulating capacitance type sensor>
Hereinafter, a method for producing the present resin composition will be described.
The present resin composition can be made into granules by mixing and kneading the above components and then using various methods such as pulverization, granulation, extrusion cutting and sieving alone or in combination. As a method for obtaining granules, for example, each raw material component is premixed with a mixer, which is heated and kneaded by a kneader such as a roll, a kneader or an extruder, and then has a cylindrical outer peripheral portion having a plurality of small holes and a disk shape. A method in which a resin composition melt-kneaded is supplied to the inside of a rotor composed of the bottom surface of the cylinder, and the resin composition is passed through a small hole by a centrifugal force obtained by rotating the rotor (centrifugal milling). Method); A method of kneading in the same manner as described above, and then cooling and pulverizing to obtain a pulverized product, which is obtained by removing coarse particles and fine powder using a sieve (crushed sieving method); each raw material component. After premixing with a mixer, heat kneading is performed using an extruder equipped with a die having multiple small diameters arranged at the tip of the screw, and the molten resin is extruded into a strand shape from the small holes arranged in the die. Is obtained by cutting with a cutter that slides and rotates substantially parallel to the die surface (hereinafter, also referred to as “hot cut method”). In any of the methods, by selecting kneading conditions, centrifugation conditions, sieving conditions, cutting conditions, etc., a granular capacitive sensor encapsulation resin composition having a desired particle size distribution can be obtained. ..

<Capacitance type sensor>
Hereinafter, the configuration of the capacitance type sensor 100 according to the present embodiment will be described in detail.

The capacitance type sensor 100 according to the present embodiment is, for example, a fingerprint sensor that reads fingerprint information by a capacitance method that senses the capacitance with a finger. Here, the fingerprint sensor reads the unevenness of the finger placed on the fingerprint sensor. For example, the capacitance type sensor 100 is provided with a detection chip 103 that is finer than the unevenness of the fingerprint. Then, a two-dimensional image showing the unevenness of the fingerprint is created by the capacitance accumulated between the unevenness of the fingerprint and the detection chip 103. For example, since the detected capacitance differs between the convex portion and the concave portion of the fingerprint, it is possible to create a two-dimensional image showing the unevenness of the fingerprint from the difference in the capacitance. Fingerprint information can be read from this two-dimensional image.

FIG. 1 is a cross-sectional view schematically showing the capacitance type sensor 100 according to the present embodiment.
The capacitance type sensor 100 according to the present embodiment includes a substrate 101, a detection chip 103 provided on the substrate 101, and a sealing film 105 for sealing the detection chip 103.
According to the present embodiment, the sealing film 105 that seals the detection chip 103 is composed of a cured product of the present resin composition. Such a cured product has excellent dielectric properties. Therefore, the sensitivity of the capacitance type sensor 100 can be improved. Here, in the present embodiment, excellent dielectric property means, for example, that the relative permittivity and the dielectric loss tangent are high, and the capacitance is large.

In order to improve the sensitivity of the capacitance type sensor 100, the thickness D of the sealing film 105 on the substrate 101 (for example, silicon chip) is, for example, 100 μm or less, more preferably 75 μm or less, still more preferably 50 μm or less. It is particularly preferably 30 μm or less.
According to the present resin composition, even when the thickness D of the sealing film 105 is equal to or less than the above upper limit value, it is possible to reduce defects such as poor filling of the resin composition for encapsulating the capacitive sensor. As a result, according to the present resin composition, it is possible to manufacture a capacitive sensor having a thin sealing film 105 and having even higher sensitivity with a high yield.

The substrate 101 is, for example, a chip-shaped silicon substrate. The detection chip 103 is formed of, for example, an Al film, and is arranged on the substrate 101 in a one-dimensional or two-dimensional array via an interlayer film 107. The interlayer film 107 is formed of, for example, SiO ₂ or the like.
The upper surface of the detection chip 103 is covered with the sealing film 105. The detection chip 103 is, for example, wire-bonded.

The capacitance type sensor 100 according to this embodiment can be manufactured based on known information. For example, it is manufactured as follows.
First, the interlayer film 107 is provided on the substrate 101, and then the detection chip 103 is formed on the interlayer film 107. Next, the detection chip 103 is hermetically sealed and molded with the present resin composition. Examples of the molding method include a compression molding method. Next, the present resin composition is thermally cured to form a sealing film 105. As a result, the capacitance type sensor 100 according to the present embodiment can be obtained.

（式（１）中、Ａｒ ^１ はフェニレン基またはナフチレン基を表し、Ａｒ ^１ がナフチレン基の場合、グリシジルエーテル基はα位、β位のいずれに結合していてもよい。Ａｒ ^２ はフェニレン基、ビフェニレン基またはナフチレン基のうちのいずれか１つの基を表す。Ｒ _ａ およびＲ _ｂ は、それぞれ独立に炭素数１～１０の炭化水素基を表す。ｇは０～５の整数であり、ｈは０～８の整数である。ｎ ^３ は重合度を表し、その平均値は１～３である。）

（式（２）中、複数存在するＲ _ｃ は、それぞれ独立に水素原子または炭素数１～４の炭化水素基を表す。ｎ ^５ は重合度を表し、その平均値は０～４である。）

（式（３）中、複数存在するＲ _ｄ およびＲ _ｅ は、それぞれ独立に水素原子又は炭素数１～４の炭化水素基を表す。ｎ ^６ は重合度を表し、その平均値は０～４である。）
１２． 前記硬化剤がフェノール樹脂であり、
前記フェノール樹脂の水酸基当量が７０ｇ／ｅｑ以上４００ｇ／ｅｑ以下である、１．乃至１１．のいずれか一つに記載の静電容量型センサ封止用樹脂組成物。
１３． 前記エポキシ樹脂のエポキシ基数をＥＰとし、前記フェノール樹脂の水酸基数をＯＨとしたとき、（ＥＰ）／（ＯＨ）によって定まる当量比が、０．７以上１．５０以下である、１２．に記載の静電容量型センサ封止用樹脂組成物。
１４． 前記充填剤が、シリカ、アルミナ、酸化チタンおよびチタン酸バリウムから選択される一種または二種以上を含む、１．乃至１３．のいずれか一つに記載の静電容量型センサ封止用樹脂組成物。
１５． 当該静電容量型センサ封止用樹脂組成物の固形分全量に対する前記充填剤の含有量が、５０質量％以上９０質量％以下である、１．乃至１４．のいずれか一つに記載の静電容量型センサ封止用樹脂組成物。
１６． 前記充填剤の平均粒径Ｄ _５０ は、０．２μｍ以上８μｍ以下である、１．乃至１５．のいずれか一つに記載の静電容量型センサ封止用樹脂組成物。
１７． 前記充填剤は、平均粒径（Ｄ _５０ ）が異なる２種以上を含む、１．乃至１６．のいずれか一つに記載の静電容量型センサ封止用樹脂組成物。
１８． 当該静電容量型センサ封止用樹脂組成物は硬化促進剤を更に含む、１．乃至１７．のいずれか一つに記載の静電容量型センサ封止用樹脂組成物。
１９． 当該静電容量型センサ封止用樹脂組成物中における前記硬化促進剤の含有量は、当該静電容量型センサ封止用樹脂組成物の固形分全量を１００質量％としたとき、０．１質量％以上５．５質量％以下である、１８．に記載の静電容量型センサ封止用樹脂組成物。
２０． 当該静電容量型センサ封止用樹脂組成物中における、前記エポキシ樹脂と、前記硬化剤と、前記硬化促進剤との合計である樹脂成分の合計含有量（ＲＣ）は、当該静電容量型センサ封止用樹脂組成物中の充填剤の含有量を１００質量％としたとき、１質量％以上１５．０質量％以下である、１８．または１９．に記載の静電容量型センサ封止用樹脂組成物。
２１． 前記静電容量型センサが静電容量型指紋センサである、１．乃至２０．のいずれか一つに記載の静電容量型センサ封止用樹脂組成物。
２２． 基板と、
前記基板上に設けられた検出電極と、
前記検出電極を封止し、かつ、１．乃至２１．のいずれか一つに記載の静電容量型センサ封止用樹脂組成物の硬化物により構成された封止膜と、
を備える静電容量型センサ。
The present invention is not limited to the above-described embodiment, and modifications, improvements, and the like to the extent that the object of the present invention can be achieved are included in the present invention.
Hereinafter, an example of the reference form will be added.
1. 1. A resin composition for encapsulating a capacitive sensor, which is used for forming a sealing film in a capacitive sensor.
Epoxy resin and
Hardener and
Filler and
Including
A resin composition for encapsulating a capacitive sensor, wherein the shrinkage rate of the test piece made of the resin composition for encapsulating the capacitive sensor obtained under the following condition 1 is less than 0.19%.
(Condition 1: The cured product obtained by heat-treating the capacitive sensor encapsulating resin composition at 175 ° C. for 2 minutes and then heat-treating at 175 ° C. for 4 hours is the test piece. ()
2. 2. 1. The breaking elongation of the test piece made of the capacitive sensor encapsulating resin composition obtained under the following condition 2 measured by a method according to JIS K7161 under a temperature condition of 150 ° C. is 2 mm or more. The resin composition for encapsulating a capacitive sensor according to the above.
(Condition 2: The capacitance type sensor encapsulation resin composition is heat-treated at 175 ° C. for 2 minutes and then heat-treated at 175 ° C. for 4 hours, and is in accordance with JIS K7161. The cured product formed so as to have a dumbbell shape is used as the test piece.)
3. 3. 1. The gel time measured by the following condition 3 of the capacitance type sensor encapsulation resin composition is 30 seconds or more and 90 seconds or less. Or 2. The resin composition for encapsulating a capacitive sensor according to the above.
(Condition 3: When the maximum torque value when the curing torque of the resin composition for encapsulating the capacitance type sensor is measured over time at a mold temperature of 175 ° C. using a curast meter is T. The time required from the start of the measurement until the value of the curing torque reaches 0.1 T is defined as the gel time.)
4. 1. The relative permittivity (ε _r ) of the cured product of the capacitive sensor encapsulating resin composition at 1 MHz is 4 or more. To 3. The resin composition for encapsulating a capacitive sensor according to any one of the above.
5. 1. The filler comprises one or more selected from silica, alumina, titanium oxide and barium titanate. To 4. The resin composition for encapsulating a capacitive sensor according to any one of the above.
6. 1. The content of the filler with respect to the total amount of the capacitance type sensor encapsulating resin composition is 50% by mass or more and 90% by mass or less. ~ 5. The resin composition for encapsulating a capacitive sensor according to any one of the above.
7. The capacitance type sensor is a capacitance type fingerprint sensor. ~ 6. The resin composition for encapsulating a capacitive sensor according to any one of the above.
8. With the board
The detection electrode provided on the substrate and
The detection electrode is sealed, and 1. ~ 7. A sealing film made of a cured product of the resin composition for sealing a capacitance type sensor according to any one of the above.
Capacitive sensor with.
In addition, an example of the reference form will be added below.
1. 1. A resin composition for encapsulating a capacitive sensor, which is used for forming a sealing film in a capacitive sensor.
Epoxy resin and
Hardener and
Filler and
Including
A resin composition for encapsulating a capacitive sensor, wherein the shrinkage rate of the test piece made of the resin composition for encapsulating the capacitive sensor obtained under the following condition 1 is less than 0.19%.
(Condition 1: The cured product obtained by heat-treating the capacitive sensor encapsulating resin composition at 175 ° C. for 2 minutes and then heat-treating at 175 ° C. for 4 hours is the test piece. ()
2. 2. 1. The breaking elongation of the test piece made of the capacitive sensor encapsulating resin composition obtained under the following condition 2 measured by a method according to JIS K7161 under a temperature condition of 150 ° C. is 2 mm or more. The resin composition for encapsulating a capacitive sensor according to the above.
(Condition 2: The capacitance type sensor encapsulation resin composition is heat-treated at 175 ° C. for 2 minutes and then heat-treated at 175 ° C. for 4 hours, and is in accordance with JIS K7161. The cured product formed so as to have a dumbbell shape is used as the test piece.)
3. 3. 1. The gel time measured by the following condition 3 of the capacitance type sensor encapsulation resin composition is 30 seconds or more and 90 seconds or less. Or 2. The resin composition for encapsulating a capacitive sensor according to the above.
(Condition 3: When the maximum torque value when the curing torque of the resin composition for encapsulating the capacitance type sensor is measured over time at a mold temperature of 175 ° C. using a curast meter is T. The time required from the start of the measurement until the value of the curing torque reaches 0.1 T is defined as the gel time.)
4. 1. The relative permittivity (ε _r ) of the cured product of the capacitive sensor encapsulating resin composition at 1 MHz is 4 or more. To 3. The resin composition for encapsulating a capacitive sensor according to any one of the above.
5. 1. The dielectric loss tangent (tan δ) of the cured product of the capacitive sensor encapsulating resin composition at 1 MHz is 0.005 or more. To 4. The resin composition for encapsulating a capacitive sensor according to any one of the above.
6. 1. The coefficient of linear expansion (CTE1) of the cured product of the capacitive sensor encapsulating resin composition at a glass transition temperature or lower is 3 ppm / ° C. or higher and 50 ppm / ° C. or lower. ~ 5. The resin composition for encapsulating a capacitive sensor according to any one of the above.
7. 1. The coefficient of linear expansion (CTE2) of the cured product of the capacitive sensor encapsulating resin composition when the glass transition temperature is exceeded is 10 ppm / ° C. or higher and 100 ppm / ° C. or lower. ~ 6. The resin composition for encapsulating a capacitive sensor according to any one of the above.
8. 1. The flexural modulus of the cured product of the capacitive sensor encapsulating resin composition at 260 ° C. is 200 MPa or more and 1500 MPa or less. ~ 7. The resin composition for encapsulating a capacitive sensor according to any one of the above.
9. The glass transition temperature of the cured product of the capacitive sensor encapsulating resin composition is 100 ° C. or higher and 250 ° C. or lower. ~ 8. The resin composition for encapsulating a capacitive sensor according to any one of the above.
10. 1. The epoxy equivalent of the epoxy resin is 70 g / eq or more and 400 g / eq or less. ~ 9. The resin composition for encapsulating a capacitive sensor according to any one of the above.
11. The epoxy resin includes an epoxy resin containing a structural unit represented by the following formula (1), an epoxy resin containing a structural unit represented by the following formula (2), and a structural unit represented by the following formula (3). 1. Containing at least one selected from the group consisting of epoxy resins comprising 1. ~ 10. The resin composition for encapsulating a capacitive sensor according to any one of the above.

(In the formula (1), Ar ¹ represents a phenylene group or a naphthylene group, and when Ar ¹ is a naphthylene group, the glycidyl ether group may be bonded to either the α-position or the β-position. Ar ² is a phenylene group. , Any one of a biphenylene group or a naphthylene group. R _a and R _b each independently represent a hydrocarbon group having 1 to 10 carbon atoms. G is an integer of 0 to 5 and h. Is an integer of 0 to 8. n ³ represents the degree of polymerization, and the average value thereof is 1 to 3.)

(In the formula (2), a plurality of R _cs independently represent a hydrogen atom or a hydrocarbon group having 1 to 4 carbon atoms. N ⁵ represents a degree of polymerization, and the average value thereof is 0 to 4. )

(In the formula (3), a plurality of R _d and _Re each independently represent a hydrogen atom or a hydrocarbon group having 1 to 4 carbon atoms. N ⁶ represents the degree of polymerization, and the average value thereof is 0 to 4. Is.)
12. The curing agent is a phenol resin,
1. The hydroxyl group equivalent of the phenol resin is 70 g / eq or more and 400 g / eq or less. ~ 11. The resin composition for encapsulating a capacitive sensor according to any one of the above.
13. When the number of epoxy groups of the epoxy resin is EP and the number of hydroxyl groups of the phenol resin is OH, the equivalent ratio determined by (EP) / (OH) is 0.7 or more and 1.50 or less. The resin composition for encapsulating a capacitive sensor according to the above.
14. 1. The filler comprises one or more selected from silica, alumina, titanium oxide and barium titanate. ~ 13. The resin composition for encapsulating a capacitive sensor according to any one of the above.
15. 1. The content of the filler with respect to the total solid content of the capacitance type sensor encapsulating resin composition is 50% by mass or more and 90% by mass or less. ~ 14. The resin composition for encapsulating a capacitive sensor according to any one of the above.
16. The average particle size _D50 of the filler is 0.2 μm or more and 8 μm or less. ~ 15. The resin composition for encapsulating a capacitive sensor according to any one of the above.
17. 1. The filler contains two or more kinds having different average particle diameters (D ₅₀ ). To 16. The resin composition for encapsulating a capacitive sensor according to any one of the above.
18. 1. The capacitance type sensor encapsulation resin composition further contains a curing accelerator. ~ 17. The resin composition for encapsulating a capacitive sensor according to any one of the above.
19. The content of the curing accelerator in the capacitance type sensor encapsulation resin composition is 0.1 when the total solid content of the capacitance type sensor encapsulation resin composition is 100% by mass. 18. Mass% or more and 5.5 mass% or less. The resin composition for encapsulating a capacitive sensor according to the above.
20. The total content (RC) of the resin component, which is the total of the epoxy resin, the curing agent, and the curing accelerator, in the capacitance type sensor encapsulating resin composition is the capacitance type. When the content of the filler in the resin composition for sealing the sensor is 100% by mass, it is 1% by mass or more and 15.0% by mass or less. Or 19. The resin composition for encapsulating a capacitive sensor according to the above.
21. The capacitance type sensor is a capacitance type fingerprint sensor. ~ 20. The resin composition for encapsulating a capacitive sensor according to any one of the above.
22. With the board
The detection electrode provided on the substrate and
The detection electrode is sealed, and 1. ~ 21. A sealing film made of a cured product of the resin composition for sealing a capacitance type sensor according to any one of the above.
Capacitive sensor with.

Hereinafter, this embodiment will be described in detail with reference to Examples and Comparative Examples. The present embodiment is not limited to the description of these examples.

(Preparation of Resin Composition for Capacitance Type Sensor Encapsulation)
First, each raw material blended according to Table 1 was kneaded at 110 ° C. for 7 minutes using a twin-screw kneading extruder. Then, the obtained kneaded product was degassed and cooled, and then pulverized with a pulverizer to obtain granules. In Examples 1 to 9 and Comparative Example 1, the granules thus obtained were further sieved to obtain a granular resin composition. The details of each component in Table 1 are as follows. The unit in Table 1 is mass%.

The raw material components used in each Example and each Comparative Example are shown below.

(Epoxy resin)
Epoxy resin 1: Biphenyl type epoxy resin containing the structural unit represented by the above formula (2) (manufactured by Mitsubishi Chemical Corporation, YX4000K, epoxy equivalent 185 g / eq).
Epoxy resin 2: A mixture of a triphenylmethane type epoxy resin and a biphenyl type epoxy resin containing the structural unit represented by the above formula (3) (JER, YL6677, epoxy equivalent 163 g / eq).
Epoxy resin 3: A biphenyl aralkyl type epoxy resin (manufactured by Nippon Kayaku Co., Ltd., NC3000L, epoxy equivalent 270 g / eq) containing a structural unit represented by the above formula (1), where Ar ¹ is a phenylene group and Ar ² is a biphenylene group. )

(Hardener)
-Curing agent 1: Triphenylmethane type phenol resin modified with formaldehyde (manufactured by Air Weater, HE910-20, hydroxyl group equivalent 101 g / eq)
-Curing agent 2: Biphenyl aralkyl type phenol resin (manufactured by Nippon Kayaku Co., Ltd., GPH-65, hydroxyl group equivalent 198 g / eq)

(Curing accelerator)
・ Curing accelerator 1: Tetraphenylphosphonium / bisphenol S salt (manufactured by Sumitomo Bakelite)
-Curing accelerator 2: Tetraphenylphosphonium / 2,3-dihydroxynaphthalene salt (manufactured by Sumitomo Bakelite)

(filler)
-Filler 1: Spherical alumina (manufactured by Nippon Steel Materials, AX3-10R, specific gravity 4, average particle size D ₅₀ : 3 μm)
-Filler 2: Spherical alumina (manufactured by Nippon Steel Materials, AX3-15R, specific gravity 4, average particle size D ₅₀ : 3.9 μm)
Filler 3: Fused spherical silica (manufactured by Admatex, SC220G-SQ, average particle size D ₅₀ : 0.5 μm)

(Other ingredients)
-Coupling agent: Phenylaminopropyltrimethoxysilane (manufactured by Toray Dow Corning, CF4083)
-Release agent 1: Stearyl alcohol-modified olefin / maleic acid copolymer (manufactured by Air Water Inc., half ester)
-Release 2: Montanic acid ester wax (manufactured by Clariant Japan, WE-4)
-Release agent 3: Diethanolamine / dimontanoic acid ester (manufactured by Itoh Oil Chemicals, NC-133)
-Colorant: Carbon black (manufactured by Tokai Carbon Co., Ltd., ERS-2001)
-Ion scavenger: Hydrotalcite (manufactured by Toagosei Co., Ltd., IXE-700F)
-Low stress agent: Acrylonitrile-butadiene rubber (manufactured by PTI Japan, CTBN10008SP)

The following evaluations and measurements were carried out using the obtained resin composition.

Shrinkage rate: First, using a transfer molding machine, a resin composition obtained under the conditions of a mold temperature of 175 ° C., a molding pressure of 9.8 MPa, and a curing time of 2 minutes was injected into a mold cavity and molded into a disk. A test piece (diameter 90 mm × thickness 12 mm) was prepared. Then, the test piece was heat-treated at 175 ° C. for 4 hours and then cooled to 25 ° C. Here, the shrinkage rate S (%) was calculated from the inner diameter of the mold cavity at 175 ° C. and the outer diameter of the test piece at 25 ° C. as follows.
S = {(inner diameter dimension of mold cavity at 175 ° C.)-(outer diameter dimension of test piece at 25 ° C.)} / (inner diameter dimension of mold cavity at 175 ° C.) × 100

Specific dielectric constant and dielectric tangent: Obtained in a mold using a compression molding machine (PMC1040 manufactured by TOWA Co., Ltd.) under the conditions of a mold temperature of 175 ° C., a molding pressure of 9.8 MPa, and a curing time of 300 seconds. A cured product of the resin composition was obtained by compression molding the resin composition. This cured product had a diameter of 50 mm and a thickness of 3 mm.
Next, the obtained cured product was measured for relative permittivity and dielectric loss tangent at 1 MHz at room temperature (25 ° C.) by Q-METER 4342A manufactured by Yokogawa-Hewlett-Packard. The results are shown in Table 1.

-Glass transition temperature (Tg) and linear expansion coefficient (CTE1, CTE2) of the cured product: Using a compression molding machine (PMC1040 manufactured by TOWA Co., Ltd.), the mold temperature was 175 ° C. and the molding pressure was 9. The obtained resin composition was compression-molded under the conditions of 8 MPa and a curing time of 300 seconds to obtain a cured product of the resin composition. This cured product had a length of 10 mm, a width of 4 mm, and a thickness of 4 mm.
Then, after the obtained cured product was post-cured at 175 ° C. for 4 hours, a thermomechanical analyzer (TMA100 manufactured by Seiko Denshi Kogyo Co., Ltd.) was used to measure the temperature range from 0 ° C. to 320 ° C. and the heating rate. The measurement was performed under the condition of 5 ° C./min. From this measurement result, the glass transition temperature (Tg), the linear expansion coefficient (CTE1) below the glass transition temperature, and the linear expansion coefficient (CTE2) when the glass transition temperature was exceeded were calculated. The results are shown in Table 1.

Flexural modulus of the cured product at 260 ° C .: First, using a compression molding machine (TOWA Co., Ltd., PMC1040), the obtained product was obtained under the conditions of a mold temperature of 175 ° C., a molding pressure of 9.8 MPa, and a curing time of 300 seconds. By compression molding the obtained resin composition, a cured product having a length of 80 mm, a width of 10 mm and a thickness of 4 mm was obtained. Then, the obtained cured product was post-cured at 175 ° C. for 4 hours. Next, the flexural modulus of the cured product at 260 ° C. was measured according to JIS K 6911. The unit of flexural modulus is MPa. The results obtained are shown in Table 1.

-Breaking elongation: First, the obtained resin composition is heat-treated at 175 ° C. for 2 minutes and then heat-treated at 175 ° C. for 4 hours to form a dumbbell shape according to JIS K7161. The cured product was obtained as a test piece. Next, the test piece was subjected to a tensile test under a temperature condition of 150 ° C. by a method conforming to JIS K7161, and the relationship between normal stress (stress) and normal strain (stress) was graphed (stress-). (Strain curve) was created. Then, the value of the breaking elongation of the test piece was obtained from the obtained curve. The unit is mm.

-Gel time: Using a curast meter (JSR curast meter IVPS type manufactured by Orientec Co., Ltd.), the curing torque of the resin composition was measured over time at a mold temperature of 175 ° C. From the obtained measurement results, when the maximum torque value in the measurement results was T, the time required from the start of the measurement until the curing torque value reached 0.1 T was calculated as the gel time. The unit is seconds.

Appearance 1 (Die Mark) of Capacitance Sensor: The obtained granular resin composition was used to prepare the capacitance sensor shown in FIG. 1. Specifically, the sealing film 105 using the resin composition is molded using a compression molding machine (PMC1040 manufactured by TOWA Co., Ltd.) at a mold temperature of 175 ° C., a molding pressure of 9.8 MPa, and a curing time. It was carried out under the condition of 300 seconds. The appearance of the capacitive fingerprint sensor provided with the sealing film 105 thus formed was visually evaluated according to the following criteria.
◯: It was confirmed that the surface of the sealing film 105 did not have a step derived from the detection chip 103.
Δ: Although there is a slight step on the surface of the sealing film 105 due to the detection chip 103, it has been confirmed that it does not affect the appearance of the capacitive fingerprint sensor in practice. rice field.
X: It was confirmed that a step derived from the detection chip 103 is generated on the surface of the sealing film 105, and the step is at a level that practically affects the appearance of the capacitive fingerprint sensor. ..

-Capacitance type sensor appearance 2 (crack): Capacitance type sensor manufactured for use in the evaluation of the above "Capacitance type sensor appearance 1 (die mark)" from -50 ° C to 150 ° C. When the process of statically storing at a variable temperature at 10 ° C./min was set as one cycle, the process was carried out for 1000 cycles. Then, in this evaluation, whether or not a crack occurred in the sealing film in the capacitive fingerprint sensor was evaluated according to the following criteria.
◯: It was confirmed that no cracks were generated in the sealing film 105 even after 1000 cycles of treatment.
Δ: It was confirmed that cracks were generated in the sealing film 105 in the treatment of 500 cycles or more and less than 1000 cycles.
X: It was confirmed that cracks were generated in the sealing film 105 in the treatment of less than 500 cycles.

Appearance 3 (flow mark) of the capacitance type sensor: The surface of the sealing film 105 in the capacitance type sensor manufactured for use in the evaluation of the above "appearance 1 (die mark) of the capacitance type sensor". It was visually observed and evaluated according to the following criteria in terms of surface contamination of the sealing film 105.
◯: It was confirmed that the surface of the sealing film 105 did not have surface stains due to the mold release component and the oil component contained in the obtained granular resin composition.
Δ: The surface of the sealing film 105 had surface stains due to the mold release component and the oil component contained in the obtained granular resin composition, although the amount was very small. It was confirmed that it does not affect the appearance of the capacitance type sensor.
X: Surface stains are generated on the surface of the sealing film 105 due to the mold release component and the oil component contained in the obtained granular resin composition, and the surface stains are practically static. It was confirmed that the level affected the appearance of the capacitance type sensor.

It was confirmed that all of the capacitive fingerprint sensors provided with the sealing film 105 produced by using the resin composition of each example had no practical appearance defect.

100 Capacitive sensor 101 Substrate 103 Detection chip 105 Encapsulating film 107 Interlayer film

Claims (15)

A resin composition for encapsulating a capacitive sensor, which is used for forming a sealing film in a capacitive sensor.
Epoxy resin and
Hardener and
Filler and
Including
The epoxy resin includes an epoxy resin containing a structural unit represented by the following formula (1), an epoxy resin containing a structural unit represented by the following formula (2), and a structural unit represented by the following formula (3). Containing at least one selected from the group consisting of epoxy resins containing
The curing agent is a phenol resin,
The hydroxyl group equivalent of the phenol resin is 70 g / eq or more and 400 g / eq or less.
When the number of epoxy groups of the epoxy resin is EP and the number of hydroxyl groups of the phenol resin is OH, the equivalent ratio determined by (EP) / (OH) is 0.7 or more and 1.50 or less.
The filler comprises one or more selected from silica, alumina, titanium oxide and barium titanate.
The content of the filler with respect to the total solid content of the capacitance type sensor encapsulating resin composition is 50% by mass or more and 90% by mass or less.
The glass transition temperature of the cured product of the capacitive sensor encapsulating resin composition is 159 ° C. or higher and 250 ° C. or lower.
A resin composition for encapsulating a capacitive sensor having a shrinkage ratio of less than 0.19% measured under the following condition 1.
(Condition 1: Condition 1:
Using a transfer molding machine, the resin composition for encapsulating the capacitive sensor is injected and molded into the mold cavity under the conditions of a mold temperature of 175 ° C., a molding pressure of 9.8 MPa, and a curing time of 2 minutes. Make a disk-shaped test piece.
Then, the obtained test piece is heat-treated at 175 ° C. for 4 hours and then cooled to 25 ° C. Here, the inner diameter of the mold cavity at 175 ° C. and the outer diameter of the test piece at 25 ° C. are measured.
Then, the shrinkage rate S (%) is calculated based on the following formula.
S = {(inner diameter dimension of mold cavity at 175 ° C.)-(outer diameter dimension of test piece at 25 ° C.)} / (inner diameter dimension of mold cavity at 175 ° C.) × 100 )

(In the formula (1), Ar ¹ represents a phenylene group or a naphthylene group, and when Ar ¹ is a naphthylene group, the glycidyl ether group may be bonded to either the α-position or the β-position. Ar ² is a phenylene group. , Any one of a biphenylene group or a naphthylene group. R _a and R _b each independently represent a hydrocarbon group having 1 to 10 carbon atoms. G is an integer of 0 to 5 and h. Is an integer of 0 to 8. n ³ represents the degree of polymerization, and the average value thereof is 1 to 3.)

(In the formula (2), a plurality of R _cs independently represent a hydrogen atom or a hydrocarbon group having 1 to 4 carbon atoms. N ⁵ represents a degree of polymerization, and the average value thereof is 0 to 4. )

(In the formula (3), a plurality of R _d and _Re each independently represent a hydrogen atom or a hydrocarbon group having 1 to 4 carbon atoms. N ⁶ represents the degree of polymerization, and the average value thereof is 0 to 4. Is.) The resin composition for encapsulating a capacitive sensor according to claim 1, wherein the gel time measured by the following condition 3 of the resin composition for encapsulating a capacitive sensor is 30 seconds or more and 90 seconds or less.
(Condition 3: When the maximum torque value when the curing torque of the resin composition for encapsulating the capacitance type sensor is measured over time at a mold temperature of 175 ° C. using a curast meter is T. The time required from the start of the measurement until the value of the curing torque reaches 0.1 T is defined as the gel time.) The capacitive sensor encapsulating resin composition according to claim 1 or 2, wherein the cured product of the capacitive sensor encapsulating resin composition has a relative permittivity (ε _r ) of 4 or more at 1 MHz. .. The capacitance type sensor seal according to any one of claims 1 to 3, wherein the cured product of the capacitance type sensor sealing resin composition has a dielectric loss tangent (tan δ) of 0.005 or more at 1 MHz. Resin composition for stopping. One of claims 1 to 4, wherein the linear expansion coefficient (CTE1) of the cured product of the capacitive sensor encapsulating resin composition at a glass transition temperature or lower is 3 ppm / ° C. or higher and 50 ppm / ° C. or lower. The resin composition for encapsulating a capacitive sensor according to the above. One of claims 1 to 5, wherein the coefficient of linear expansion (CTE2) of the cured product of the capacitive sensor encapsulating resin composition when the glass transition temperature is exceeded is 10 ppm / ° C. or higher and 100 ppm / ° C. or lower. The resin composition for encapsulating a capacitive sensor according to the above. The capacitance type sensor encapsulation according to any one of claims 1 to 6, wherein the cured product of the resin composition for encapsulating the capacitance type sensor has a flexural modulus of 200 MPa or more and 1500 MPa or less at 260 ° C. Resin composition for. The resin composition for encapsulating a capacitive sensor according to any one of claims 1 to 7, wherein the epoxy equivalent of the epoxy resin is 70 g / eq or more and 400 g / eq or less. The resin composition for encapsulating a capacitive sensor according to any one of claims 1 to 8 , wherein the average particle size D ₅₀ of the filler is 0.2 μm or more and 8 μm or less. The resin composition for encapsulating a capacitive sensor according to any one of claims 1 to 9 , wherein the filler contains two or more kinds having different average particle sizes (D ₅₀ ). The resin composition for encapsulating a capacitive sensor according to any one of claims 1 to 10 , further comprising a curing accelerator. The content of the curing accelerator in the capacitance type sensor encapsulation resin composition is 0.1 when the total solid content of the capacitance type sensor encapsulation resin composition is 100% by mass. The resin composition for encapsulating a capacitive sensor according to claim 11 , wherein the mass% or more and 5.5% by mass or less. The total content (RC) of the resin component, which is the total of the epoxy resin, the curing agent, and the curing accelerator, in the capacitance type sensor encapsulating resin composition is the capacitance type. The capacitive sensor encapsulation according to claim 11 or 12 , wherein the content of the filler in the resin composition for encapsulating the sensor is 1% by mass or more and 15.0% by mass or less when the content is 100% by mass. Resin composition for. The resin composition for encapsulating a capacitive sensor according to any one of claims 1 to 13 , wherein the capacitive sensor is a capacitive fingerprint sensor. With the board
The detection electrode provided on the substrate and
A sealing film that seals the detection electrode and is made of a cured product of the resin composition for encapsulating a capacitive sensor according to any one of claims 1 to 14 .
Capacitive sensor with.

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