JPH08153832A - Resin sealed semiconductor device, electronic circuit device and manufacturing method thereof - Google Patents

Abstract

PURPOSE: To reduce the warping of a substrate by a method wherein a semiconductor element is arranged on a substrate and then sheet-like non-cured resin is arranged thereon and in order to cure-mold resin sheet in a metallic mold, the complex elastic modulus and dynamic tangent loss at the room temperature after the formation of a resin layer is specified. CONSTITUTION: A sealing resin sheet 5 is arranged on a substrate 1 whereon a semiconductor element 3 is packaged using a bonding wire 4. Besides, solder bumps 2 for input-output terminals are quardratically arranged. Next, outside metallic molds 7 are tightened to bury the gap between a package for avoiding the burring. Finally, the inside metallic mold 8 is tightened for curing the resin while pressurizing. At this time, the complex elastic modulus of a resin layer at the room air temperature after the molding step is at most 6.5&times;10<9> Pa while the dynamic tangent loss is at least 0.05. Through these procedures, the warping of the package substrate can be reduced.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a resin-encapsulated semiconductor device and an electronic circuit device, and more particularly to a single-sided encapsulated semiconductor device, an electronic circuit device mounted with a ball grid array (BGA) package and a method for manufacturing the same. Regarding

[0002]

2. Description of the Related Art Conventionally, as a surface mount type multi-terminal LSI package, a QFP (Quad Flat Package) in which leads are led out from four side surfaces of the package is widely known. This QFP package has been used in various devices because it has a low manufacturing cost and the number of input / output terminals can be increased without changing the size of the package by narrowing the pitch between terminals. For example, the pitch interval is 0.4 mm from the previous 1 mm.
The number of terminals has increased to 250 pins. However, the lead terminal of the QFP is easily deformed, and if the terminal is deformed, the package may not be normally soldered to the printed board.

Recently, as the number of I / O pins has increased, the OLB (Outer Lead Bonding) pitch has become narrower, and it has become difficult to connect to the circuit wiring board with the conventional QFP.

Therefore, a semiconductor element is replaced by an OMPAC (Ove
rmolded Pad Array Carrier
r) has been newly proposed as a method of enabling connection to a wiring board (Electronic Pac).
kaging and Production p25
May 1992). This OMPAC package
Instead of the pins of a PGA (Pin Grid Array) package, a solder bump electrode formed on the back surface of the package substrate is used to connect the package and the circuit wiring board, and a BGA (Ball Grid A) is used.
known as rray) packaging and is becoming the mainstream of high density packaging technology.

In the BGA package, the spherical solder bumps, which are terminals, are arranged in a two-dimensional array on the back surface of the package substrate, so the terminal pitch is QFP.
Much wider than Further, the BGA package having terminals formed of solder can be soldered together with other surface mount type components by making the solder composition uniform. Therefore, the defect occurrence rate during mounting is much lower than that of the plastic QFP. Further, by increasing the number of terminals, heat can be released from the LSI chip to the solder terminals through the heat dissipation through holes, and the thermal resistance can be reduced, which is also advantageous for a high heat generation package.

Since such a plastic BGA has solder terminals for input and output on the back surface of the substrate, the LSI chip is mounted on the metal frame which is the substrate, and the upper and lower sides of the substrate are sealed with the mold resin. The structure is different from the conventional LSI package such as QFP. That is, the plastic BGA substrate is made of resin made of the same material as the printed wiring board, and after mounting the LSI chip thereon, only the upper surface of the substrate on which the chip is mounted is covered with the molding resin.

Therefore, in the plastic BGA, the warp of the substrate due to the shrinkage of the resin is an unavoidable problem. The warp of the substrate increases as the package size increases, that is, as the number of terminals increases. The variation in height of the bottom surface of the solder terminal may reach, for example, 130 μm, and it is expected that it is difficult to manufacture a multi-terminal LSI package having more than 300 pins.

Therefore, the increase in the number of terminals is hindered, and the current number of terminals of the BGA is the number of terminals that can be sufficiently supplied by the QFP, so that the advantages of the plastic BGA cannot be sufficiently obtained under the present circumstances. .

On the other hand, when a BGA package is mounted on a circuit wiring board to manufacture an electronic circuit device, since it is connected by bumps, stress distortion occurs in the bump electrode portions as in the case of conventional flip chip mounting. There is a problem. This stress strain causes destruction of the bump electrode and further shortens the reliability life of the electronic circuit device.

It is known that the reliability life can be improved by reducing the maximum shear strain γ _max generated in the bump electrode in the cycle life expression represented by the following expression (1) (IBM). J. Res. Develo
p. , 13; 251 (1969)).

Nf = Cf ^1/3 γ _max · exp (1428 / T _max ) (1) (C; constant, f; frequency, T _max ; maximum temperature) where the maximum shear strain γ _max is It is represented by 2).

Γ _max = {1 / (D _min / 2) ^{2 / β} } (V / πh ^{1 + β} ) ^{1 / β} · d · ΔT · Δα (2) (D _min ; minimum bump diameter, β; material Constant, V: solder volume, h: solder height Δα: difference in thermal expansion coefficient, ΔT: temperature difference, d: distance from chip center to bump center) Therefore, in the conventional flip chip mounting technology, Such means have been used to reduce the stress generated in the bump electrode. That is, (1) reduce the distance from the center point of the semiconductor chip to the center of the bump electrode, (2) reduce the difference between the coefficient of thermal expansion of the semiconductor chip and the coefficient of thermal expansion of the circuit wiring board, (3) connect. Improve the heat dissipation so that the temperature change of the part does not become large,
(4) Improving the structure of the bump electrode so that the generated stress strain can be sufficiently absorbed, (5) Strengthening the flip-chip mounting structure by filling the gap between the semiconductor chip and the circuit wiring board with resin, etc. Is a means of.

Among these methods, in particular, as in (5), when the resin is filled in the gap between the semiconductor chip and the circuit wiring board and the chip and the circuit wiring board are integrated by the resin,
Since the amount of displacement of the semiconductor chip and the amount of displacement of the circuit wiring board due to stress strain can be matched, the reliability of the electronic circuit device is improved. In recent flip-chip mounting, a glass epoxy substrate having an extremely large coefficient of thermal expansion is used, and thus the method of filling the gap between the chip and the substrate with resin is extremely effective for improving reliability. Is said to be.

A conventional flip-chip mounting structure using the method (5) has a structure as shown in FIG. That is, the semiconductor chip 52 is mounted on the surface of the circuit wiring board 51 by the bumps 53, and the gap between the substrate 51 and the semiconductor chip 52 is filled with the resin 54.

Specifically, for example, a method of filling a resin (Japanese Patent Laid-Open No. 61-194732), a method of sealing an ultraviolet curable resin (Japanese Patent Laid-Open No. 62-252946),
A method of sealing the gap with a room temperature curable resin (JP-A-63-13)
No. 337), and many methods such as a method for optimizing the physical properties of the resin to be sealed (Japanese Patent Laid-Open No. 4-219944).

However, in the method of crimping the semiconductor chip onto the circuit wiring board on which the uncured thermosetting resin has been potted in advance, the resin is likely to remain in the electrode terminal portions of the bump electrodes and the circuit wiring board, resulting in a connection resistance. There was the problem of becoming expensive.

Therefore, the semiconductor chip is placed on the circuit wiring board, uncured resin having fluidity is potted near the gap between the semiconductor chip and the circuit wiring board, and the resin is filled in the entire gap by utilizing the capillary phenomenon. Method of curing resin after impregnation with (Electronic Compo
nents and Technology Conf
erence Proceeding, 1993 p1
75) has been proposed, and it is conceivable to apply this method when mounting a BGA package.

[0018]

In order to solve the problem of substrate warpage that occurs during resin encapsulation in a BGA package, several packages having a devised structure have been developed. As one of them, it is proposed to increase the thickness of the substrate, but the thickness of the entire package increases, which causes problems such as deterioration of heat dissipation characteristics and increase of cost. When a ceramic substrate is used, warpage of the substrate can be prevented, but in this case, the cost and manufacturing process increase.

Further, in the case of the conventional package such as QFP, since the space formed by the upper and lower molds being completely meshed with each other is filled with the resin, the resin burr flowing out from the gap between the molds is sealed. Was not a problem, but B
Since the GA package is sealed by pouring resin between the mold and the plastic substrate, there is a problem that resin burrs are increased due to the precision and deformation of the plastic substrate.

On the other hand, when the BGA package is mounted on the circuit wiring board, the reliability cannot be improved even if the conventional flip chip mounting technique is applied.
That is, when the gap between the package and the circuit wiring board is impregnated with resin, the size of the gap is 100 to 200 μm.
m, which is larger than that in the case of flip chip mounting (20 to 50 μm), so that the resin could not be impregnated into the entire gap due to the capillary phenomenon. In addition to the gap size, the BGA package size is larger than that of the semiconductor chip, so that the stress generated by the temperature cycle is larger than that in the flip chip mounting. For this reason, the resin placed in the gap cannot fully relax the stress, and the resin itself is destroyed.

Even if the bump electrode height is lowered in order to facilitate the impregnation of the resin into the gap, the impregnation rate cannot be sufficiently increased, and the thermal expansion coefficient of the resin is 20 ppm by adding the quartz filler. When the temperature was decreased from / ° C to 40 ppm / ° C, the impregnation rate became extremely slow.

Since the resin is potted on one side of the package having a square shape, when the impregnation speed of the resin is slow, the resin is not evenly arranged around the package on the other three sides. As a result, stress is concentrated on one side of the package, and the entire package peels off the substrate.

Further, when the pressure contact time is made sufficiently long and the pressure contact is carried out gently, the resin is deformed during the reflow process, and whichever method is used, the circuit wiring board of the BGA package is not deformed. In mounting, it is difficult to reduce the stress applied to the bumps by disposing the resin in the gap with the substrate. Even if the impregnation is possible, there is a problem in the process because the impregnation takes a very long time.

Therefore, the present invention is a semiconductor device in which only the surface of a substrate on which a semiconductor chip is mounted is resin-sealed,
An object of the present invention is to provide a resin-encapsulated semiconductor device in which warpage of a package substrate is reduced.

Further, the present invention provides an electronic circuit device in which the stress strain generated in the bump between the BGA package substrate and the circuit wiring substrate is reduced and the reliability life is improved, and a manufacturing method thereof. To aim.

[0026]

In order to solve the above problems, the present invention (claim 1) includes a substrate, a semiconductor element arranged on the surface of the substrate, and a resin layer for sealing the semiconductor element. In the resin-encapsulated semiconductor device, wherein the resin layer is disposed only on the side where the semiconductor element is disposed with respect to the substrate, the resin-encapsulated semiconductor device includes a step of disposing the semiconductor element on the substrate, and a sheet. Manufactured by a manufacturing method consisting of a step of disposing a uncured resin in the shape of a semiconductor on a semiconductor element, and a step of curing and molding a resin sheet in a mold, and the resin layer,
Complex elastic modulus at room temperature after molding is 6.5 × 10 ⁹ Pa
Provided is a resin-encapsulated semiconductor device having a mechanical tangent loss Tan δ of 0.05 or more.

Further, according to the present invention (claim 4), a substrate having solder bumps for input / output terminals arranged two-dimensionally on the back surface,
A resin encapsulation, comprising: a semiconductor element mounted on the surface of the substrate, wherein the surface of the substrate on which the semiconductor element is mounted is sealed with a resin sheet having a shrinkage prevention plate attached to one surface thereof. Provide a semiconductor device.

Further, according to the present invention (claim 5), a package substrate having solder bumps for input / output terminals arranged two-dimensionally on the back surface, and a semiconductor package including a semiconductor element mounted on the surface of the substrate, In an electronic circuit device comprising a circuit wiring board on which the package is connected and mounted, a thermosetting resin sheet having a stepwise different thermal expansion coefficient in a thickness direction is provided in a gap between the package board and the circuit wiring board. Provided is an electronic circuit device characterized by being arranged.

The present invention will be described in detail below.

In the resin-sealed semiconductor device of the present invention,
Examples of the material of the substrate on which the semiconductor element is mounted include plastics, film carriers, ceramics and the like, and specifically, lead frames, TAB and the like can be used.

The present invention is particularly effective in the case of a ball grid array (BGA) package in which spherical solder bumps for input / output terminals are two-dimensionally arranged on the surface mounted on the circuit wiring board. .

In the present invention, the type of semiconductor element mounted on the substrate is not particularly limited.

The first aspect of the resin-encapsulated semiconductor device of the present invention will be described in detail below.

The uncured resin used for sealing the surface of the substrate on which the semiconductor element is mounted is a melt viscosity when heated considering the damage to the wires, inner leads and the chip surface, and the moldability. Is 3000 Pa
・ It is desired that the value is s or less. The melt viscosity is 10
It is more preferable for it to be 00 Pa · s or less because a good package can be obtained. On the other hand, in order to prevent the resin from flowing out between the die and the substrate on which the semiconductor chip is mounted, it is necessary to have a high viscosity to some extent, and it is required to be 20 Pa · s or more. Particularly, when it is 50 Pa · s or more, the occurrence of burrs is small.

In the present invention, a semiconductor device is manufactured using an uncured resin which has been molded into a sheet shape in advance.

FIG. 1 is a process diagram showing a specific example of a sealing method using a resin sheet.

First, as shown in FIG. 1A, the sealing resin sheet 5 is placed on the substrate 1 on which the semiconductor element 3 is mounted by the bonding wires 4. It should be noted that solder bumps 2 for input / output terminals are two-dimensionally arranged on the back surface of the substrate 1.

Next, as shown in FIG. 1B, the outer die 7
Tighten to close the gap with the package and suppress the occurrence of burrs. Finally, as shown in FIG. 1 (c), the inner mold 8 is tightened, and the resin is cured while being pressed, thereby
The resin-encapsulated semiconductor device of this aspect is obtained.

During compression molding, the inside of the mold may be depressurized in order to prevent the generation of voids. Furthermore, in order to improve various characteristics of the package after molding,
After cure is desirable.

The size of the mold used is preferably equal to or slightly larger than the size of the resin sheet. On the other hand, the volume inside the mold is set to be slightly smaller than the volume of the resin sheet so that the size at the time of molding can be improved. It is desirable to use a resin designed to be pressurized. Further, an air bend may be provided in the mold so that excess resin can be discharged when pressure is applied.

By using the resin sheet in this way, the sealing process can be performed in-line, so that a flexible manufacturing method suitable for small-lot production of a wide variety of products can be obtained. That is,
It is possible to perform sealing in a continuous process by mounting a single-sided wiring board to which semiconductor chips are connected on a belt and feeding it while supplying a sealing resin sheet cut to a predetermined size by a magazine method. .

In the present invention, a resin layer in which the elastic modulus and the dynamic tangent loss Tan δ of the resin after molding are in a specific range is used.

The elasticity and viscosity of the material will be described in detail below.

Any material is a viscoelastic body that has elasticity and viscosity more or less in combination, and when dynamic viscoelasticity measurement with sinusoidal vibration is performed, force (stress) as a stimulus is obtained.
In response, a phase shift occurs between the distortion and the distortion.

Assuming that the material is a combination of an elastic body and a viscous body as shown in FIG. 2A, and the steady vibration strain γ (t) = γ ₀ e ^iωt , the stress relaxation time is τ. Then _{stress, σ (t) = Gγ 0} (iωτ / (1 + iωτ)) e iωt next, indicates that performs a vibration of the angular velocity ω in amplitude as the _{Gγ 0 (iωτ / (1 +} iωτ)).

A value obtained by dividing stress as a definition of elastic modulus by strain, that is, σ (t) / γ (t) is a complex elastic modulus G ^* , G ^* (iω) = G (iωτ / (1 + iωτ)) ) = G ′ (ω) + iG ″ (ω) where G ′ (ω) = G (ω ² τ ² / (1 + ω ² τ ² )) G ″ (ω) = G (ωτ / (1 + ω ² τ ² )) Functions G ′ (ω) and G ″ (ω) are referred to as storage modulus and loss modulus, respectively, and can be expressed as σ (t) = σ ₀ e ^{i (ωt + δ),} and stress It can be seen that there is a phase corner angle δ between the amplitude of and the amplitude of the distortion, and the mechanical tangent loss Tan δ is given by Tan δ = G ″ (ω) / G ′ (ω).

FIG. 2B shows the phase relationship between the absolute amplitudes of stress and strain. Experimentally, steady time changes of stress and strain as shown in FIG. 2B were recorded, and σ ₀ , γ
₀ and (δ / ω) are obtained and substituted into the respective equations to obtain the complex elastic modulus and Tan δ.

In the present invention, the elastic modulus of the resin after molding is preferably 6.5 × 10 ⁹ Pa or less, and the warp ratio of the substrate after sealing is preferably within 6%. The warpage rate is
Referring to FIG. 3, it is represented by ((L'-L) / L),
Here, L and L ′ are the sum of the thickness of the substrate and the thickness of the sealing resin, and the maximum value after the substrate is warped. Therefore, the elastic modulus is a ₁ (Pa) and the thermal expansion coefficient is b.
₁ (1 / K), and the coefficient of thermal expansion of the wiring board is b ₂ (1
/ K), | b ₁ −b ₂ | × a ₁ <5 × 10 ⁵
It is desirable to select each value so as to satisfy the relationship of. Furthermore, in order to sufficiently reduce the warpage, the elastic modulus a ₁ is less than 5 × 10 ⁹ Pa and | b ₁ −b ₂ |
It is preferable that xa ₁ <3 × 10 ⁵ . Elastic modulus a ₁
Is less than 5 × 10 ⁹ Pa and | b ₁ −b ₂ | × a ₁
When it is <1 × 10 ⁵ , warp can be completely prevented, which is the most preferable.

Tan δ after molding of these resins is 0.0
It is preferably 5 or more, and 0.1 or more is preferable because the warp can be sufficiently reduced. Furthermore, Tan after molding
When δ is 0.2 or more, warpage can be completely prevented, which is more preferable.

Examples of such a resin include a thermosetting resin.

The thermosetting resin which can be used in the present invention includes, for example, epoxy resin, polyimide resin, maleimide resin, silicone resin, phenol resin, polyurethane resin, acrylic resin and the like. Alternatively, they may be used in combination. In addition, when using these thermosetting resins, it is possible to cure by using a method of heating a mold used during molding, or selectively heating only the uncured resin by induction heating. it can.

Among the above-mentioned thermosetting resins, it is particularly preferable to use an epoxy resin, and any one can be used as long as it has at least two epoxy groups in one molecule. Examples thereof include bisphenol A type epoxy resin, novolac type epoxy resin, alicyclic type epoxy resin, and glycidyl ester type epoxy resin, and these can be used alone or in a mixture of two or more kinds.

Rubber having a low elastic modulus is preferably added to the resin used in the semiconductor device of the present invention.

By using the rubber component, not only the elastic modulus of the sealing resin is lowered but also the adhesion between the substrate and the resin is increased, so that the total water absorption of the package is lowered. Therefore, the occurrence of cracks during reflow can be suppressed, and the reliability of the semiconductor device can be further improved.

Examples of rubbers preferably used include styrene-butadiene rubber, butadiene rubber, isoprene rubber, acrylonitrile-butadiene copolymer rubber, chloroprene rubber, butyl rubber, urethane rubber, silicone rubber, polysulfide rubber, hydrogenated nitrile rubber, and fluorine. Examples thereof include rubber, vinylidene fluoride rubber, acrylic rubber, and natural rubber. In addition, as a thermoplastic elastomer, styrene type, olefin type, urethane type, polyester type,
Polyamide-based, polybutadiene-based, vinyl chloride-based, fluorine-based, etc. may be used.

Among these rubbers, fluororubber and silicone rubber are particularly preferable. Fluorine rubber has outstanding heat resistance, chemical resistance, and oxidation resistance. And silicone rubber is excellent in heat resistance and cold resistance, and exhibits compression recovery in a wide temperature range.
Good oil resistance, water resistance, weather resistance, and corona resistance,
It has excellent electrical characteristics. Both rubbers are optimal for semiconductor encapsulation.

These rubbers may be used alone or in combination, or may be used in combination with an epoxy resin.

As the vulcanizing agent for curing such rubber, a sulfur-based vulcanizing agent, a peroxide, a metal oxide, a polyfunctional amine, a quinone dioxime, a methylol resin or the like can be used. Particularly, sulfur-based vulcanizing agents and peroxide vulcanizing agents are preferable.

Specific examples of the sulfur type include powdered sulfur, insoluble sulfur (gamma type crystal), colloidal sulfur, sulfur chloride,
Examples thereof include selenium, tellurium, thiuram disulfide, thiuram tetrasulfide, morpholine derivative, selenium dithiocarbamate, and alkylphenol polysulfide.

As the peroxide, an inorganic peroxide,
Examples thereof include organic silicon peroxides and organic peroxides. Preferred organic peroxides to be used are benzoyl peroxide, benzoyl peroxide, 1,1-di-t-butylperoxy-3,3,5-trimethylcyclohexane, di-t-butylperoxide (TBP), t-butylck. Mill Peroxide (BCPO), Dicumyl Peroxide (DCP), 2,5-Dimethyl-2,5-di (t-
Butylperoxy) hexane (TBPH), 2,5-dimethyl-2,5-di (t-butylperoxy) hexane (TBPH-3), 1,3-bis (t-butylperoxy-iso-propyl) benzene (BPOPB) ), T-
Butyl peroxy-iso-propyl carbonate and the like.

It is also possible to add a vulcanization accelerator to these. Examples of the vulcanization accelerator include 2-mercaptobenzothiazole, dibenzothiazole disulfide, copper salt of 2-mercaptobenzothiazole, N-cyclohexyl-2-benzothiazyl-sulfenamide,
N-oxydiethylene-2-benzothiazyl-sulfenamide, N, N-diisopropyl-2-benzothiazyl-sulfenamide, N, N-diethylthiocarbamoyl-2-benzothiazyl sulfide, hexamethylenetetramine, diphenylguanidine, Tetramethylthiuram-monosulfide, zinc dimethyldithiocarbamate, etc. can be used.

When these rubber components are added to the encapsulating resin, the ratio of the encapsulating resin to the organic component is 5% or more, and in consideration of reduction of warpage and improvement of adhesion, it is 10% or more. It is preferably included. Especially 20%
The above is more preferable because the warpage can be completely eliminated, the water absorption rate can be reduced, and sufficient reliability can be obtained.

The resin used in the present invention includes, in addition to the above-mentioned rubber component, a curing agent, a curing accelerator, a plasticizer, a release agent,
Flame retardants, fillers, low stress additives, and various other additives can be added.

Examples of the curing agent include amine acid, acid anhydride, fatty acid, and alkyd resin. When epoxy resin is used, it is preferable to use phenol resin. Specific examples thereof include novolac-type phenol resins having two or more phenolic hydroxyl groups such as phenol novolac resin and cresol novolac resin.

As the curing accelerator, any accelerator that accelerates the reaction between the epoxy resin and the curing agent can be used. Examples thereof include various amines, imidazoles, diazabicycloalkenes, organic phosphines, zirconium alcoholates, and zirconium chelates. As the amines, N, N-dimethylcyclohexylamine, N-methyldicyclohexylamine,
Triethylenediamine, diaminodiphenyl sulfone,
Examples thereof include dimethylaminomethylphenol, benzyldimethylamine, and trisdimethylaminomethylphenol. Examples of imidazoles include 2-methylimidazole, 2-phenylimidazole, heptadecylimidazole, 2-heptadecylimidazole, 2-ethylimidazole, And 2-ethyl-4-methylimidazole and the like. Examples of diazabicycloalkenes include 1,8-diazabicyclo (5,4,0) undensene-7 (DBU), and phenol salts of DBU (for example, U-CATSA No. 1), and the like. Examples of the phosphines include triphenylphosphine (TPP), tributylphosphine, tricyclohexylphosphine, and methyldiphenylphosphine.

Of these curing accelerators, triphenylphosphine and heptadecyl imidazole are particularly preferable from the viewpoint of electrical characteristics.

Examples of the plasticizer include paraffin oil, naphthene oil, aromatic oil, wax, pine oil, pine tar, pitch, pine resin, coal tar oil, fatty acid, coumarone, indene resin, and factice. Can be mentioned.

Examples of the releasing agent include hydrocarbon wax, fatty acid wax, fatty acid amide wax, ester wax and the like. As specific examples, from the viewpoint of moisture resistance, carnauba wax, ester waxes such as montan wax are preferable, and stearic acid, palmitic acid, zinc stearate, long-chain carboxylic acids such as calcium stearate and metal salts thereof, Examples thereof include low molecular weight polyethylene wax. These release agents may be used alone or in combination.

As the flame retardant, halogen-based, phosphorus-based or inorganic flame-retardant can be used. Halogen-based flame retardants are mainly classified into bromine-based and chlorine-based flame retardants, and preferable bromine-based flame retardants include, for example, brominated bisphenol A type epoxy resin. This bromine-based flame retardant is preferable because it has a higher flame retardant effect than a chlorine-based flame retardant and a large effect in combination with antimony trioxide. Examples of chlorine-based flame retardants that are preferably used include chlorinated paraffin.

Preferred inorganic inorganic flame retardants are red phosphorus, tin acid, antimony trioxide, zirconium hydroxide, barium metaborate, aluminum hydroxide, magnesium hydroxide, calcium hydroxide, and calcium aluminum. Nate hydrate and the like, and particularly preferable are antimony trioxide and aluminum hydroxide.

In the present invention, the filler and the low stress additive which can be used preferably have a maximum particle diameter of 90% or less of the resin thickness on the element active surface side after the semiconductor element is sealed. If the particles having a particle diameter larger than the resin thickness are used, a force may be applied to the semiconductor active surface and the wiring may be cut.

As the filler, an inorganic filler can be used, and its shape is not limited. That is, crushed, rounded crushed, sub-spherical, spherical, fibrous, scaly, and plate-like inorganic fillers can be used. Examples of the material of the inorganic filler include silicon oxide, aluminum oxide, antimony oxide, titanium oxide, magnesium oxide, calcium oxide, aluminum nitride, silicon nitride, various glass materials, and ceramic materials. Among these, a highly pure silicon oxide material, that is, a powder of fused silica or crystalline silica is suitably used as a filler for semiconductor encapsulation. In the case of encapsulating a semiconductor package having a high heat generation, it is preferable to use an inorganic filler having a higher thermal conductivity such as aluminum nitride, silicon nitride and alumina.

Various colorants may be added to the resin used in the present invention. As the colorant, a black pigment colorant is preferable as a light-shielding agent, and carbon black is particularly preferable. Further, a resin containing a colorant of various colors can be used in combination with a resin of a black colorant, and an inorganic pigment, an organic pigment, a dye or the like can be used.

Inorganic pigments are not generally clear in color, but are excellent in light resistance, heat resistance and solvent resistance and have a large hiding power. The inorganic pigments preferably used include the following. ZnO, TiO ₂ , 2PbCO ₃ · P
b (OH) ₂ and white pigments such as ZnS + BaSO ₄ ; PbCrO ₄ , CdS + ZnO, and K ₃ [Co
(No ₂ ) ₆ ] and other yellow pigments; PbCrO ₄ + PbSO
Orange pigment such as ₄ + PbMoO ₄ ; CdS + CdSe, F
e ₂ O ₃ , and red pigments such as Pb ₃ O ₄ ; KFe [F
e (CN) ₆ ], NaFe [Fe (CN) ₆ ], and NH ₄ Fe [Fe (CN) ₆ ] and other blue pigments; CoO +
Green pigments such as ZnO and Cr ₂ O ₃ ; black pigments such as Fe ₃ O _{4 and the} like. Furthermore, examples include moisture-resistant pigments such as calcium carbonate, barium sulfate, aluminum hydroxide, barite powder, aluminum powder, and bronze powder. These pigments may be used alone or in combination of a plurality of pigments.

Examples of organic pigments which are preferably used include those shown below. That is, azo system,
Red or orange pigments such as anthraquinone type and quinacridones; purple pigments such as triphenylmethane type lake, oxazine dye, and anthraquinone dye; blue pigments such as phthalocyanine pigment, indanthrone anthraquinone dye, and triphenylmethane type lake; Phthalocyanine-based and anthraquinone-based green pigments; black includes black pigments such as diamond black, which is an oxidative condensation product of aniline. These pigments may be used alone or in combination of a plurality of pigments.

Further, in the present invention, the uncured resin may be reinforced with various inorganic and organic woven fabrics for use.

Examples of the inorganic type include glass, quartz, carbon fiber, silicon carbide, silicon nitride, aluminum nitride, alumina, zirconia, and potassium titanate fiber. Examples of the organic type include nylon type, acrylic type, vinylon. Series, polyvinyl chloride series, polyester series, aramid series, phenol series, rayon series, acetate series, cotton,
Examples include hemp, silk, and wool. These materials may be used alone or in combination.

The uncured resin used in the first aspect of the semiconductor device of the present invention is, for example, an epoxy resin, a curing agent, a flame retardant, a curing accelerator, a coloring agent, a filler / a low stress additive, and other materials. Can be produced by crushing, mixing and melting.

Further, the melted resin is rolled and molded into a sheet for use.

Since the obtained resin sheet is extremely brittle, it is preferable to use the following means when it is cut into a predetermined size. First, the resin sheet is heated on release paper and cut by pressing a cold blade, or the resin sheet is left at room temperature and cut using a heated blade. The heating temperature of the resin sheet or the blade is preferably a temperature at which the resin is sufficiently melted so that curing of the resin does not proceed, and specifically, 70 ° C to 130 ° C is preferable.

When a prepreg reinforced with a woven fabric such as a glass woven fabric is used, a resin, a curing agent, a curing accelerator, a flame retardant, a filler and other materials are dissolved in a solvent such as acetone. A prepreg can be prepared by preparing a solution having an appropriate concentration and applying the solution to a woven cloth, or impregnating the woven cloth in the solution, and allowing the solvent to volatilize under standing, heating, or reduced pressure. .

The resin layer in the resin-encapsulated semiconductor device of the present invention is characterized in that a resin having a low elastic modulus is used after molding.

These low elastic modulus resins have a large decrease in strength under heat. Therefore, if they are molded by the conventional transfer molding method, the package may be broken at the time of mold release, or the resin of the runner portion used for carrying the package may be soft. It becomes difficult to carry. However, in the molding method using the resin sheet, the package can be ejected from the mold by the inner mold 8 shown in FIG. 1, so that the package is significantly less damaged than the eject method using the pins like the transfer molding method. Become. Further, in this sealing method having no runner portion, there is almost no influence of the decrease in strength under heat due to the low elastic modulus of the resin.

In the potting method using a resin dissolved in a solvent, if a rubber is used for sealing in order to achieve a low elastic modulus, the solvent remains in a large and soft mesh structure during molding, resulting in a package. As the reliability is reduced. Furthermore, when rubber particles such as MBS dispersed in a sealing resin for lowering the elastic modulus are used, the dispersed rubber particles agglomerate again when a solvent is added, so that the sealing resin As a result, the strength as a resin is reduced. In the potting method, the resin is usually 200 μm or less in order to evaporate the solvent, and TCP (Tape Carrier Packa) is used.
Only the ge) type was sealed. However, since the BGA package is generally of the wire bonding type, the resin thickness that sufficiently covers the wire is at least 50.
It is required to be 0 μm or more, and sealing by the potting method is impossible. Further, the potting method has a drawback that the dimensional accuracy after molding is low.

Therefore, by using the method of sealing with a resin sheet, these drawbacks are covered,
It can be sealed using a low elastic modulus resin.

Next, a second mode of the semiconductor device of the present invention will be described.

Examples of the uncured resin that can be used in the second aspect include the same thermosetting resins as in the first aspect, as well as thermoplastic resins, rubbers, engineering plastics and the like.

The uncured resin used here can be manufactured in the form of a sheet using the same material as in the case of the above-mentioned first embodiment except that the complex elastic modulus and the value of Tan δ are not limited. That is, for example, it can be produced by crushing, mixing, melting, and rolling an epoxy resin, a curing agent, a flame retardant, a curing accelerator, a filler, a low stress additive, and other materials.

The size and thickness of the sheet can be appropriately selected according to the size of the bump electrodes provided on the back surface of the substrate.

The obtained sheet is cut into a predetermined size in the same manner as in the case of the first embodiment, and then a shrinkage-preventing plate is attached to one surface for sealing.

Examples of the material of the shrinkage-preventing plate that can be attached to one surface of the sheet-shaped uncured resin include metals, ceramics, and plastics.

As the metal, one having a high elastic modulus and a high thermal conductivity is preferable in consideration of heat dissipation. Specifically, for example, iron, copper, aluminum, nickel, chromium, zinc, tin, silver, gold, lead, magnesium, titanium,
Examples thereof include alloys of these metals such as zirconia, tungsten, molybdenum, cobalt, stainless steel, 42 nickel-iron alloy, brass and duralumin. However, when aiming to make the package thinner, it can be processed especially thinly,
It is also desirable to use a lightweight material.

A semiconductor device can be manufactured according to the process shown in FIG. 4 by using the resin sheet having the shrinkage prevention plate attached to one surface thereof.

First, as shown in FIG. 4A, the substrate 1 on which the semiconductor element 3 is mounted by the bonding wire 4 is mounted.
The sealing resin sheet 5 to which the shrinkage prevention plate 11 is attached is arranged on the above. It should be noted that solder bumps 2 for input / output terminals are two-dimensionally arranged on the back surface of the substrate 1.

Next, as shown in FIG. 4B, the outer die 7
Tighten to close the gap with the package and suppress the occurrence of burrs. Finally, as shown in FIG. 4 (c), the inner mold 8 is tightened, and the resin is cured while being pressurized, so that the second mold is formed.
The resin-encapsulated semiconductor device of this aspect is obtained.

According to this method, since the resin sheet is sandwiched between the substrate to which the semiconductor chip is connected and the shrinkage prevention plate, the elasticity modulus, thickness and thermal expansion coefficient of the shrinkage prevention plate are set to appropriate values. As a result, a package having no warp after molding can be obtained.

In the case of sealing with the resin sheet with the plate attached in this way, the elastic modulus of the plate is a ₃ (Pa), the thickness is t ₃ (mm), and the thermal expansion coefficient is b ₃ (1 / K),
The elastic modulus, thickness, and coefficient of thermal expansion of the circuit board to which the semiconductor chip is connected are a ₂ (Pa) and t ₂ (m, respectively).
m) and b ₂ (1 / K), it is desired that the relationship be as shown in the following equation.

0.8 <a ₃ t ₃ b ₃ / a ₂ t ₂ b ₂ <1.2 In the above, the method of reducing the warpage of the package substrate has been described by focusing on the sealing of the semiconductor device. The method of reducing the warp is not limited to this. That is, in addition to the sealing of the surface of the substrate on which the chip is mounted, the thermosetting resin sheet is sandwiched between the package substrate and the circuit substrate and thermocompression bonding is performed to reduce the warpage of the substrate.

In this case, the characteristics of the mounting resin arranged between the circuit board and the board and the sealing resin for sealing the surface of the board to which the semiconductor chip is connected are set to appropriate values so that after mounting, The warpage is reduced, and the defect occurrence rate during mounting can be reduced. As a characteristic,
The elastic modulus, the thickness, and the thermal expansion coefficient of the resin are mentioned. Specifically, the elastic modulus of the sealing resin after molding is a ₄ (Pa), the thickness is t ₄ (mm), and the thermal expansion coefficient is b ₄ (1 / K),
After mounting, the resin has an elastic modulus of a ₅ (Pa) and a thickness of t ₅ (m
m) and the coefficient of thermal expansion is b ₅ (1 / K), it is desired that the relationship be represented by the following equation.

0.8 <a ₄ t ₄ b ₄ / a ₅ t ₅ b ₅ <1.2 It is to be noted that the resin sheet used for mounting should be provided with an opening portion in advance at a portion corresponding to the solder terminal. Although preferable, the solder terminal is a ball that is harder than a resin sheet, and therefore has less deformation. Therefore, even if a resin sheet having no holes is used, the solder terminals can be pressed against the resin sheet to make holes in the sheet and reach the circuit board below to be connected.

A specific example of a mounting method using a resin sheet is shown in FIG.

First, as shown in FIG. 5A, between the circuit board 12 and the substrate 1 on which the semiconductor element 3 is mounted by the bonding wires 4 and the mounting surface is sealed by the sealing resin sheet 5. The mounting resin sheet 6 is arranged.

Next, as shown in FIG. 5 (b), the resin is hardened by thermocompression bonding with the upper and lower molds 9 and 10. The resin disposed between the package and the circuit board strengthens the connection, so that some warpage or deformation of the package can be returned and the board can be flattened.

As described above, when a resin sheet is arranged between the package board and the circuit board to manufacture an electronic circuit device, the thermal expansion coefficient is inclined in the thickness direction of the sheet to provide the package board with a thermal expansion coefficient. It is possible to prevent the warp and to gradually reduce the stress strain generated in the bump connection portion, thereby further improving the reliability of the device.

Hereinafter, the electronic circuit device of the present invention using the resin sheet having the thermal expansion coefficient gradually changed in the thickness direction will be described in detail.

The material of the package substrate used in the electronic circuit device of the present invention is not limited as long as solder bumps for input / output terminals are two-dimensionally arranged on the back surface thereof. For example, plastic, film carrier,
And ceramics etc. can be used.

The type of semiconductor element mounted on the substrate is not particularly limited.

The method of connecting the semiconductor chip to the BGA package substrate is not particularly limited, and wire bonding, flip chip technology or the like can be used. When the flip-chip technology is used for mounting, it is preferable to fill a resin between the semiconductor chip and the circuit board.

The surface of the package substrate on which the semiconductor chip is mounted may be sealed with a resin seal or a metal cap.

Solder bumps can be formed on the back surface of the package substrate, for example, as described below. That is, the package is inverted, a paste is applied and printed on a portion corresponding to the electrode pad of the module substrate using a metal mask for screen printing, and then the whole is reflowed. Here, solder balls may be used instead of the solder paste.

BGA used in the electronic circuit device of the present invention
An example of the package is shown in FIG. In the BGA package 21, the package substrate 2 made of AlN
The semiconductor chip 23 is connected to the surface of 2 by a bonding ear 27, and is further sealed by a resin cap 27. Further, solder bumps 25 are formed on the back surface of the package substrate 22.

The material of the circuit wiring board for mounting the BGA package is not particularly limited.
For example, glass epoxy, polyimide, alumina, aluminum nitride, etc. can be used.

FIG. 6B shows an example of the circuit wiring board.
As shown, the circuit wiring board 28 made of glass epoxy
An electrode pad 29 is formed on the surface of the.

In the present invention, the resin sheet arranged between the package substrate and the circuit wiring substrate may be any resin as long as it is a thermosetting resin. Specific examples thereof include epoxy resin, polyimide resin, maleimide resin, silicone resin, phenol resin, polyurethane resin, acrylic resin, and novolac resin.

The resin sheet used in the present invention is produced, for example, by crushing, mixing and melting a resin, a curing agent, a filler, a curing catalyst and, if necessary, other additives, and then rolling them. be able to.

As the curing agent, when an epoxy resin is used, it is preferable to use a phenol resin.
Further, examples of the filler include a quartz filler and a fused filler, and the particle size of the filler can be about 0.1 to 200 μm. Examples of the curing catalyst include triphenylphosphine, heptadecylimidazole, N, N-dimethylcyclohexylamine, and the like.

The resin sheet used in the electronic circuit device of the present invention is one in which the coefficient of thermal expansion in the thickness direction is changed stepwise to give an inclination, and the value of the coefficient of thermal expansion in this resin sheet is the package. It is preferably between the values of the coefficient of thermal expansion of the board and the circuit wiring board.

The value of the coefficient of thermal expansion in the thickness direction of the resin sheet can be changed by changing the amount of the above-mentioned filler stepwise in the thickness direction of the sheet, and the coefficient of thermal expansion can be changed stepwise. It is preferable to manufacture by laminating a plurality of changed sheets. In this case, it is preferable that the number of sheets to be laminated is large, but if there are at least three layers, the stress generated in the bump connecting portion can be relieved.

The direction of change of the coefficient of thermal expansion of the resin sheet can be selected according to the coefficient of thermal expansion of the package board and the circuit wiring board. For example, on a circuit wiring board made of glass epoxy (coefficient of thermal expansion: 40 × 10 ⁻⁶ ppm / ° C.), AlN (coefficient of thermal expansion: 5 × 10 ⁻⁶ p
pm / ° C) When mounting a package composed of a board, increasing the thermal expansion coefficient of the resin sheet from the package board side toward the circuit wiring board side disperses the stress,
It is possible to prevent the bump formation surface on the back surface of the package substrate and the passivation film on the circuit wiring board surface from peeling off. When the direction of change of the thermal expansion coefficient in the resin sheet is opposite, it is more preferable because the effect of reducing the warp of the circuit wiring board portion of the portion where the package is mounted can be obtained.

When the relationship between the coefficient of thermal expansion of the package substrate and the coefficient of thermal expansion of the circuit wiring board is opposite to the above,
It is preferable that the direction of change of the coefficient of thermal expansion in the resin sheet is also opposite.

The above-mentioned resin sheet has a dimension of 20% compared with the vertical and horizontal dimensions of the package substrate on which it is mounted.
It is preferable to increase by 40%. Within this range, stress generated due to the difference in thermal expansion coefficient between the package board and the circuit wiring board can be uniformly distributed on four sides, so that the stress can be prevented from being concentrated on one side. It is possible to prevent the package from peeling off from the circuit wiring board.

The thickness of the resin sheet can be appropriately selected according to the size of the bump electrode and is not particularly limited.

The resin sheet used in the electronic circuit device of the present invention is preferably provided with through holes 41 at positions corresponding to the bumps of the package, as shown in FIG. 7 (a).
A cross section taken along the line AA ′ is shown in FIG. Since the resin sheet 40 has the through-holes 41 formed therein, the bump electrodes of the package substrate and the pad electrodes of the circuit wiring substrate do not remain in the resin and can be connected more reliably.

When the solder composition of the bump electrode is close to the eutectic composition and has a low melting point, the solder may be deformed during pressurization, resulting in incomplete contact between the bump electrode and the electrode pad of the circuit wiring board. By providing the through holes in the resin sheet, such contact failure can be prevented. Therefore, the bump electrode and the electrode pad can be surely electrically connected.

The through holes are preferably formed to have the same size as the diameter of the bump electrodes, but there may be a difference of about ± 5 μm.

Such through-holes can be formed in the resin sheet by etching, but in the case of holes having a pitch of 100 μm or more, it is desirable that the through-holes be formed by a batch method using a press.

Further, when a package having a narrow bump pitch is mounted on a circuit wiring board, even if the above-mentioned sheet having through holes is used, the connection between the bump electrode and the electrode pad becomes incomplete, so that the bump electrode height is high. It may be difficult to form high aspect ratio bumps with increased height.

In such a case, as shown in FIG. 7C, the through holes 4 provided at the corresponding positions of the bump electrodes.
It is preferable to use a resin sheet in which the metal conductor 43 is embedded in 1. As a result, it is not necessary to embed the solder bumps in the resin sheet, and the bump electrodes and the electrode pads of the circuit wiring board can be reliably connected. In this case, it is desirable that the upper portion of the metal conductor embedded in the resin sheet has a volume larger than the volume of solder to be connected and is slightly concave from the flat surface of the resin.

As the metal to be embedded in the through hole, the solder having the same composition as the bump is most desirable, but any Pb / Sn solder having the same composition as the bump can be used. In some cases, Au, Cu, N
A laminated metal made of i, Ag, Ti, or a combination thereof can also be used.

Next, a method of manufacturing the electronic circuit device of the present invention using the above resin sheet will be described with reference to the drawings.

8 to 9 are sectional views showing manufacturing steps of the electronic circuit device of the present invention.

First, as shown in FIG. 8A, the circuit wiring board 28 is heated by the heater 32, and the uncured resin sheet 30 is pressed onto the mounting surface thereof at, for example, 10 kg / mm ^2. While arranging. Thereby, the resin sheet 30 can be adhered to the surface of the circuit wiring board 28, and the resin sheet does not move from a predetermined position after the alignment.

Next, using a bonder having a half mirror to perform alignment, as shown in FIG. 8B, the resin sheet 30 arranged on the circuit wiring board 28 is placed on the resin sheet 30.
The bump electrodes 25 of the GA package 21 are aligned with the corresponding electrode pads 29 of the circuit wiring board 28. The heater 32 under the circuit wiring board 28 and the collet 34 holding the package are heated to 180 ° C. However, since the bump electrode 25 is lower than the eutectic temperature, the solder bump electrode does not melt.

Subsequently, as shown in FIG. 9A, the collet is moved downward so that the bump electrode 25 is arranged in the semi-molten resin sheet 30, for example, 30 kg / mm.
^The pressure is applied by ² to bring the bump electrode 25 of the package 21 into contact with the electrode pad 29 of the circuit wiring board 28. By further raising the temperature, the solder is melted and the electrode pad 29 of the circuit wiring board 28 and the bump electrode 25 are connected.

By carrying out the above steps, FIG.
The electronic circuit device 35 shown in (b) is obtained.

In the manufacturing method described above, the BGA package in which the semiconductor chip is mounted on the package board by the bonding wire is mounted on the circuit wiring board.
The method of mounting the semiconductor chip is not limited to this. For example, a BGA package in which semiconductor chips are connected by a flip chip mounting method can also be used,
An example of the electronic circuit device obtained in this case is shown in FIG.
In this case, as shown in FIG.
It is desirable that a resin 38 be disposed in the gap between the package 3 and the package substrate 22.

[0137]

The resin-encapsulated semiconductor device of the present invention is encapsulated with a resin having a limited elastic modulus and tan δ after molding, so that a BGA package with reduced warpage can be obtained. The defect occurrence rate of can be significantly reduced.

In particular, when using a resin which is preliminarily processed into a sheet shape so that it has a shape close to that after molding, the moving distance of the resin during molding is much smaller than in the transfer molding method.
Moreover, since it is not necessary to provide a runner for flowing the resin, the viscosity of the resin can be increased. Therefore, by processing the uncured resin into a sheet shape and curing it while heating and pressing the semiconductor element in the press die while sealing it, it is possible to prevent warpage of the substrate and also to prevent burrs from occurring. it can.

Further, the problem of conveyance and ejection which is difficult in the transfer method due to the decrease in the heat strength of the package due to the low elastic modulus, and the method of ejecting in the plane of the mold in the method using the sheet should be adopted. Can be solved by

Even when the physical properties of the resin are not limited, by using a resin sheet having a shrinkage prevention plate attached to one surface thereof, the resin sheet is sandwiched between the substrate on which the semiconductor element is mounted and the shrinkage prevention plate. Since it can be cured, a package in which warpage is prevented can be obtained.

Therefore, according to the present invention, the reliability of the resin-encapsulated semiconductor device can be guaranteed for a long period of time.

In the electronic circuit device of the present invention,
Since the resin sheet having the slope of the thermal expansion coefficient in the thickness direction is arranged between the BGA package substrate and the circuit wiring substrate, the stress generated in the bump connecting portion can be gradually relaxed. As a result, the reliability life of the electronic circuit device can be improved.

Further, since the uncured resin is molded into a sheet in advance and used, it does not require a long time as in the case of impregnating the liquid resin in the gap, which leads to a reduction in manufacturing cost. By molding the resin into a sheet shape in this manner, the resin can be easily arranged between the BGA package and the circuit wiring board even if the particle size of the filler contained in the resin is large.

When a liquid resin is used, it is difficult to uniformly dispose the resin in the gap between the package substrate and the circuit wiring board because the impregnation is not sufficient. Although there is a problem that sufficient reliability cannot be obtained due to the remaining voids, in the present invention, after arranging the uncured resin sheet with the determined dimensions on the circuit wiring board, Since the package is mounted on the resin sheet and sealing is performed while applying pressure, the resin can be uniformly arranged in the gap portion, and voids do not remain.

Therefore, it is possible to reduce the stress strain generated in the bump connection portion and improve the reliability of the electronic circuit device.

[0146]

The present invention will be described in more detail below by showing specific examples of the present invention.

(Example I) First, the following components were used as raw materials and mixed in the respective proportions to prepare a resin sheet.

(Resin 1) Dimethyl polysiloxane as silicone rubber (TSE200, manufactured by Toshiba Silicone Co., Ltd.)
To 100 parts, 3 parts of benzoyl peroxide which is an organic peroxide as a vulcanizing agent was added, 350 parts of fused silica (GR-80AK) was further used as a filler, and A-187 (manufactured by UCC) as a silane coupling agent. ) 3.5 parts,
Carbon black (CB-30) as a colorant is added to 1.5
Parts, each component was kneaded using a two-roll at 45 ° C,
An uncured silicone rubber composition was obtained.

The elastic modulus of this resin at room temperature after molding was 2.5 × 10 ⁸ Pa, and the coefficient of thermal expansion was 3.3 × 10 ^5.
(1 / K) and Tan δ was 0.22.

(Resin 2) Vinylidene fluoride and hexafluoropropylene as fluororubber (manufactured by DuPont, V
100 parts of iton A), 2.5 parts of benzoyl peroxide which is a peroxide as a vulcanizing agent, 350 parts of fused silica (GR-80AK) as a filler, and A-187 as a silane coupling agent. (UCC) 3.5 parts, carbon black (CB-3 as a colorant
0) 1.5 parts were added, and each component was used for 130 minutes using a two-roll mill.
The mixture was kneaded at 0 ° C. to obtain an uncured fluororubber composition.

The elastic modulus of this resin at room temperature after molding was 3.0 × 10 ⁸ Pa, and the thermal expansion coefficient was 3.1 × 10 ^5.
(1 / K) and Tan δ was 0.25.

(Resin 3) ESX-2 as an epoxy resin
21 (Sumitomo Chemical, epoxy equivalent 220, softening point 85
C) 70 parts, AER-74 as flame retardant epoxy resin
5 (Asahi Kasei Co., brominated epoxy resin) 30 parts, as a phenol resin XL-225L (Mitsui Toatsu Chemicals, phenol aralkyl resin, softening point 84 ° C., hydroxyl group equivalent 1
80) 56 parts, A-18 as a silane coupling agent
7 (manufactured by UCC) 3.5 parts, carbon black (CB-30) 1.5 parts as a colorant, and C as a curing accelerator.
17Z (Shikoku Kasei, heptadecyl imidazole) 2
Parts, 14 parts of heat-curing type addition type silicone gel as silicone gel, 45 parts of MBS average particle size 30 μm,
2 parts ester wax as a release agent, 14 parts antimony trioxide as a flame retardant, fused silica GR as a filler
370 parts of -80AK were used. Silicone gel and M
BS was used after being dispersed in a curing agent in advance. That is, after heating and melting the phenol resin at a temperature above the softening point in a universal mixer and adding the silicone gel and MBS powder,
The mixture was stirred and mixed, further kneaded with a three-roll mill, and uniformly dispersed to reduce the maximum particle size. Then, add each ingredient to 2
This roll was kneaded to obtain an uncured resin composition.

The elastic modulus of this resin at room temperature after molding was 2.40 × 10 ⁹ Pa, and the coefficient of thermal expansion was 2.4 × 10.
⁵ (1 / K) and Tan δ was 0.13.

(Resin 4) An uncured resin composition having the same composition as the resin composition 3 described above except that 12 parts of a heat-curing type addition type silicone gel and 40 parts of an MBS average particle size of 30 μm were used as the silicone gel. Got

The elastic modulus of this resin at room temperature after molding was 3.80 × 10 ⁹ Pa, and the thermal expansion coefficient was 2.2 × 10.
⁵ (1 / K) and Tan δ was 0.09.

(Resin 5) An uncured resin composition having the same composition as the resin composition 3 described above except that 10 parts of a heat-curing type addition type silicone gel and 30 parts of an MBS average particle size of 30 μm were used as the silicone gel. Got

The elastic modulus of this resin at room temperature after molding was 6.10 × 10 ⁹ Pa, and the coefficient of thermal expansion was 2.0 × 10.
⁵ (1 / K) and Tan δ was 0.06.

(Resin 6) An uncured resin composition having the same composition as the resin composition 3 described above except that 7 parts of a heat-curing type addition type silicone gel and 10 parts of an MBS average particle size of 30 μm were used as the silicone gel. Got

The elastic modulus of this resin at room temperature after molding is 1.20 × 10 ¹⁰ Pa, and the thermal expansion coefficient is 1.8 × 10.
⁵ (1 / K) and Tan δ was 0.04.

(Resin 7) An uncured resin composition having the same composition as the resin composition 3 described above except that 2 parts of a heat-curing type addition type silicone gel and 5 parts of an MBS average particle size of 30 μm were used as the silicone gel. Got

The elastic modulus of this resin at room temperature after molding was 1.60 × 10 ¹⁰ Pa, and the thermal expansion coefficient was 1.4 × 10.
⁵ (1 / K) and Tan δ was 0.03.

The above-mentioned compositions of resins 1 to 7 were rolled into sheets each having a predetermined thickness by using a press, and further 80
Rolled to a thickness of 0 μm to obtain one resin sheet. Next, the sheet was cut into a size of 32 mm × 32 mm by pressing a cooled blade against the heated sheet.

(Example I-1) BGA (output / input terminal 39)
6-pin, 1.5 mm pitch, glass epoxy substrate with a thermal expansion coefficient of 1.2 × 10 ^-5 semiconductor chip (15 mm ×
(15 mm × 400 μm), a sealing resin sheet having the composition of Resin 1 was placed on it, and heat-pressed for 1 minute at 182 ° C. in a press die. Furthermore, after-curing was performed at 190 ° C. for 8 hours to obtain a package. The size of the resin portion of the obtained package is 35 mm × 35 mm, and the thickness is 1
It was 200 μm.

After that, the package was mounted on a mounting substrate (made of glass epoxy) by solder reflow. The distance between the package and the substrate after mounting was 410 μm.

(Example I-2) BGA (output terminal 39)
6-pin, 1.5 mm pitch, glass epoxy substrate with a thermal expansion coefficient of 1.2 × 10 ^-5 semiconductor chip (15 mm ×
(15 mm × 400 μm), a sealing resin sheet having the composition of Resin 2 was placed on it, and thermocompression bonding was performed in a press die at 190 ° C. for 3 minutes. Further, after-curing was performed at 180 ° C. for 8 hours to obtain a package.

The size of the resin portion of the obtained package is
The size is 35 mm × 35 mm, and the thickness is 1200 μm.

After that, the package was mounted on a mounting substrate (made of glass epoxy) by solder reflow. The distance between the package and the substrate after mounting was 410 μm.

(Embodiment I-3) BGA (output terminal 39)
6-pin, 1.5 mm pitch, glass epoxy substrate with a thermal expansion coefficient of 1.2 × 10 ^-5 semiconductor chip (15 mm ×
(15 mm × 400 μm), a sealing resin sheet having the composition of Resin 3 was placed on it, and heat-pressed for 1 minute at 182 ° C. in a press die. Further, after-curing was performed at 180 ° C. for 8 hours to obtain a package.

The size of the resin portion of the obtained package is
The size was 35 mm × 35 mm, and the thickness was 1200 μm.

After that, the package was mounted on a mounting substrate (made of glass epoxy) by solder reflow. The distance between the package and the substrate after mounting was 410 μm.

(Example I-4) BGA (output terminal 39)
6-pin, 1.5 mm pitch, glass epoxy substrate with a thermal expansion coefficient of 1.2 × 10 ^-5 semiconductor chip (15 mm ×
(15 mm × 400 μm), a sealing resin sheet having the composition of Resin 4 was placed on the above, and heat-pressed for 1 minute at 182 ° C. in a press die. Further, after-curing was performed at 180 ° C. for 8 hours to obtain a package.

The size of the resin portion of the obtained package is
The size was 35 mm × 35 mm, and the thickness was 1200 μm.

Thereafter, the package was mounted on a mounting board (made of glass epoxy) by solder reflow. The distance between the package and the substrate after mounting was 410 μm.

(Embodiment I-5) BGA (output / input terminal 39)
6-pin, 1.5 mm pitch, glass epoxy substrate with a thermal expansion coefficient of 1.2 × 10 ^-5 semiconductor chip (15 mm ×
(15 mm × 400 μm), a sealing resin sheet having the composition of Resin 5 was placed on the sheet, and heat-pressed for 1 minute at 182 ° C. in the press die. Further, after-curing was performed at 180 ° C. for 8 hours to obtain a package.

The size of the resin portion of the obtained package is
The size was 35 mm × 35 mm, and the thickness was 1200 μm.

After that, the package was mounted on a mounting substrate (made of glass epoxy) by solder reflow. The distance between the package and the substrate after mounting was 410 μm.

(Embodiment I-6) BGA (output terminal 39)
6-pin, 1.5 mm pitch, semiconductor chip (15 mm × 15 mm) with AlN substrate thermal expansion coefficient 0.4 × 10 ^-5
A resin sheet for encapsulation having a composition of Resin 1 was placed on (× 400 μm) and thermocompression bonded with a press die at 182 ° C. for 1 minute. Further, after-curing was performed at 180 ° C. for 8 hours to obtain a package.

The size of the resin portion of the obtained package is
The size was 35 mm × 35 mm, and the thickness was 1200 μm.

Then, the package was mounted on a mounting board (made of glass epoxy) by solder reflow. The distance between the package and the substrate after mounting was 410 μm.

(Embodiment I-7) BGA (output terminal 39)
6-pin, 1.5 mm pitch, glass epoxy substrate with a thermal expansion coefficient of 1.2 × 10 ^-5 semiconductor chip (15 mm ×
15 mm × 400 μm), a sealing resin sheet having a composition of resin 6 and a copper plate (thickness: 200) as a shrinkage prevention plate.
(μm) was placed and heat-pressed for 1 minute at 182 ° C. in the press die. Further, after-curing was performed at 180 ° C. for 8 hours to obtain a package.

The size of the resin portion of the obtained package is
The size was 35 mm × 35 mm, and the thickness was 1400 μm.

After that, the package was mounted on a mounting board (made of glass epoxy) by solder reflow. The distance between the package and the substrate after mounting was 410 μm.

(Embodiment I-8) BGA (output terminal 39)
6-pin, 1.5 mm pitch, glass epoxy substrate with a thermal expansion coefficient of 1.2 × 10 ^-5 semiconductor chip (15 mm ×
15 mm × 400 μm), a sealing resin sheet having the composition of resin 7 and a stainless plate (thickness 200 μm) as a shrinkage-preventing plate are placed, and at 182 ° C. in a press die,
It was thermocompression bonded for a minute. Further, after-curing was performed at 180 ° C. for 8 hours to obtain a package.

The size of the resin portion of the obtained package is
The size was 35 mm × 35 mm, and the thickness was 1400 μm.

Then, the package was mounted on a mounting substrate (made of glass epoxy) by solder reflow. The distance between the package and the substrate after mounting was 410 μm.

(Comparative Example I-1) BGA (output terminal 39
6-pin, 1.5 mm pitch, glass epoxy substrate with a thermal expansion coefficient of 1.2 × 10 ^-5 semiconductor chip (15 mm ×
15 mm × 400 μm), a resin sheet for encapsulation having a composition of Resin 6 was placed, and heat-pressed for 1 minute at 182 ° C. in a press die. Further, after-curing was performed at 180 ° C. for 8 hours to obtain a package.

The size of the resin portion of the obtained package is
The size was 35 mm × 35 mm, and the thickness was 1200 μm.

After that, the package was mounted on a mounting substrate (made of glass epoxy) by infrared reflow. The distance between the package and the substrate after mounting was 410 μm.

(Comparative Example I-2) BGA (output terminal 39)
6-pin, 1.5 mm pitch, glass epoxy substrate with a thermal expansion coefficient of 1.2 × 10 ^-5 semiconductor chip (15 mm ×
(15 mm × 400 μm), a sealing resin sheet having the composition of Resin 7 was placed on the sheet, and heat-pressed for 1 minute at 182 ° C. in the press die. Further, after-curing was performed at 180 ° C. for 8 hours to obtain a package.

The size of the resin portion of the obtained package is
The size was 35 mm × 35 mm, and the thickness was 1200 μm.

After that, the package was mounted on a mounting substrate (made of glass epoxy) by infrared reflow. The distance between the package and the substrate after mounting was 410 μm.

The following tests were performed using the packages obtained in Examples I-1 to I-8 and Comparative Examples I-1 to I-2 and the package after mounting.

1) Cold / heat cycle test The prepared package was subjected to a cold / heat cycle, and the operation characteristics of the device were checked to examine the defect occurrence rate. In addition, the cooling / heating cycle made 1 cycle from -65 degreeC-room temperature-150 degreeC, and repeated this for 100-1000 cycles.

2) Cooling / Heat Cycle Test After Mounting The package after mounting was subjected to a cooling / heating cycle, and the operating characteristics of the device were checked to check the defect occurrence rate. In addition, the cooling / heating cycle made 1 cycle from -65 degreeC-room temperature-150 degreeC, and repeated this for 100-1000 cycles.

3) Warpage Measurement of Package The warpage of the package after molding was measured by the method shown in FIG.

4) Warpage measurement of package after mounting The warpage of the package after mounting was measured by the method shown in FIG. 3 (b).

The results of the above tests and measurements are shown in Table 1 below.
Put together.

[0198]

[Table 1] As shown in Table 1, the packages of Examples I-1 to I-6 in which the resins having the elastic modulus after molding and Tan δ within the predetermined ranges are used have a small warp ratio, which may exceed 6%. Since it does not exist, defects in the thermal cycle test rarely occur. Since the warpage rate becomes smaller after mounting, the defect occurrence rate in the thermal cycle test is low and the reliability is very good.

Similarly, in the case of the packages of Examples I-7 and I-8 using the resin sheet to which the plate material is attached, since the warpage ratio is small, it is defective in the thermal cycle test and the thermal cycle test after mounting. It can be seen that the occurrence rate is low and high reliability is obtained.

On the other hand, the elastic modulus and Ta after molding
Comparative Examples I-1 and I-2 using Resins 6 and 7 in which nδ is outside the range of the present invention are defective in the 200-hour cooling / heating cycle test, and sufficient reliability is not obtained. . The packages of these comparative examples all have a large warpage ratio of about 10%, and due to this large warpage,
It can be seen that the defect occurrence rate is high. Further, the defect occurrence rate in the thermal cycle test after mounting is also high.

(Example II) The electronic circuit device of the present invention will be described in more detail below by showing specific examples of the present invention.

(Production of Resin Sheet) First, a cresol novolac type epoxy resin (EOCN-195X) is used.
L; manufactured by Sumitomo Chemical Co., Ltd.) 100 parts by weight, phenol resin 54 parts by weight as a curing agent, fused silica 35 as a filler
0 parts by weight, 0.5 benzyldimethylamine as a catalyst
Parts by weight, 3 parts by weight of carbon black as another additive, and 3 parts by weight of a silane coupling agent are crushed, mixed, melted and rolled, and further 35 × 35 m
It was cut into m to prepare an uncured resin sheet having a thickness of 50 μm. The obtained resin sheet was designated as sheet a.

Further, two kinds of sheets having the same composition and the same film thickness as the above except that the ratio of the fused silica was changed were prepared. The ratio of fused silica is 200 for each.
The resin sheets thus obtained were designated as sheets b and c, respectively.

The thermal expansion coefficients of the resin sheets a to c were as follows.

Silica content (parts by weight) Coefficient of thermal expansion (ppm / ° C.) Resin sheet a 350 26 × 10 ⁻⁶ Resin sheet b 200 31 × 10 ⁻⁶ Resin sheet c 100 36 × 10 ⁻⁶ Such thermal expansion The resin sheets a, b and c having a coefficient were laminated in this order to obtain a mounting resin sheet having a thickness of 150 μm. When laminating, the resin is kept in an uncured state by not keeping the temperature higher than the curing temperature. Since the contents of fused silica differ from each other in the laminating direction, it is possible to obtain a mounting resin sheet in which the thermal expansion coefficients differ stepwise in the thickness direction.

[0206] This mounting resin sheet is arranged such that the side having a small thermal expansion coefficient (resin sheet a) is in contact with the glass epoxy substrate, and the semiconductor chip is mounted on the surface in advance.
The A package was mounted on a glass epoxy substrate by the steps shown in FIGS. 7 and 8 described above, and the obtained electronic circuit device was designated as Example II-1.

The package substrate is 30 mm
An AlN product having terminals with 256 pins on the back surface at the corners was used. Here, the thermal expansion coefficients of AlN, which is a package substrate, and glass epoxy, which is a module substrate, are 5 × 10 ⁻⁶ (ppm / ° C.) and 40 × 10 5, respectively.
^-6 (ppm / ° C).

Further, contrary to the above, similarly, except that the side of the mounting resin sheet having the large thermal expansion coefficient (the resin sheet c) is arranged to be in contact with the glass epoxy substrate,
An electronic circuit device of Example II-2 was manufactured.

A cooling / heating cycle test was conducted on the obtained electronic circuit device, and the reliability was evaluated as defective if the connection was opened even at one of 256 pins.
In addition, the number of samples is set to 1000, and -25 ° C (30
Min) -25 ° C (5 minutes) -125 ° C (30 minutes) -25 ° C
The test was conducted with (5 minutes) as one cycle. FIG. 11 shows the relationship between the number of cycles and the cumulative defective rate.

In FIG. 11, curves a and b represent the results of Example II-1 and Example II-2, respectively.

Curves c, d, and e are the results for the electronic circuit device of the comparative example obtained by mounting the same package as the example on the same glass epoxy substrate under the following conditions. is there.

Curve c: no resin sheet used Curve d: resin sheet containing no filler (thickness 150 μm
m) Curve e: resin sheet with a filler content of 40% (thickness 150
μm) As shown in FIG. 11, it can be seen that the electronic circuit device of the present invention (curves a and b) does not cause defects up to 3000 cycles. In particular, when the module substrate having a large coefficient of thermal expansion is arranged so that the side having a smaller coefficient of thermal expansion of the mounting resin sheet is in contact (curve a), the occurrence of defects is small.

On the other hand, in the sample (curve c) which was not resin-sealed, a defect occurred after 500 cycles and 10
After 100 cycles or more, it became 100% defective.

When the resin sheet is used (curve d) and when the filler is uniformly contained in the resin (curve e), the reliability is improved as compared with the curve c, but 3
The incidence of defects at 000 cycles exceeds 75%.

Next, the relationship between the dimension of the mounting resin sheet existing around the package and the reliability life was examined by changing the materials of the package substrate and the module substrate.

FIG. 12 shows the obtained results. The sample was manufactured in the same manner as in Example II-1 described above, and the shape, number, and reliability test environment of the sample were all tested in the same manner as in the case of FIG. The reliability was evaluated by Nf ₅₀ showing a cumulative failure of 50%.

Curves f, g, h and i represent the results when the package substrate and the module substrate are combined as follows, respectively.

Package Substrate Module Substrate Curve f AlN Glass Epoxy Curve g Alumina Glass Epoxy Curve h Glass Epoxy Glass Epoxy Curve i AlN Glass Epoxy (provided that a resin having a uniform coefficient of thermal expansion is placed) When the size of the resin sheet existing around is less than 20%, a defect of peeling from the package substrate occurs. On the other hand, when the size of the resin sheet is greater than 40%, the entire resin is peeled from the circuit wiring substrate. There has occurred. When the size of the resin sheet existing around the package was 20% to 40% of the vertical and horizontal sizes of the package, high reliability life was obtained in all examples.

Subsequently, the package dimensions and the results of the reliability life Nf ₅₀ were examined, and the results are shown in FIG. An electronic circuit device was manufactured in the same manner as in Example II-1 except that the dimensions of the package were changed, and the measurement result thereof was represented by curve j.

Further, the same measurement was carried out for the case of mounting using a resin sheet containing 50% of a filler of 50 μm in place of the resin sheet for mounting of the present invention and the case of mounting without using the resin sheet. Curves k and m
Expressed as

As shown in FIG. 13, in the electronic circuit device of the present invention (curve j), defects are hardly generated even in the case of a package exceeding 20 mm square, but when a resin to which a filler is uniformly added is used. 15 mm for (curve k)
If the corner is exceeded, defects will often occur. In the case of mounting without using the resin sheet (curve m), a defect occurs when it exceeds 10 mm square.

FIG. 14 shows the relationship between the number of bumps arranged in the package and the bump connection rate.

In the figure, the curve n ₁ represents the result for the electronic circuit device manufactured in the same manner as in Example II-1. The curve o ₁ represents the result when a through hole is formed in the bump portion of the same mounting resin sheet, and further, the curve p
₁ represents the result when the solder as the metal conductor is embedded in the penetrating portion provided in the resin sheet.

As shown in FIG. 14, in the case of only resin sheets having a difference in thermal expansion coefficient (curve n ₁ ), when the number of bump electrodes exceeds 1000, the connection rate begins to decrease, but the through holes are provided. In the case of using the obtained sheet (curve o ₁ ), the connection rate does not decrease up to 1500 bump electrodes. Furthermore, when a resin sheet having a metal conductor embedded in the through hole is used (curve p ₁ ), the number of electrodes is 2000.
Even if the number of bumps is exceeded, the bump connection rate hardly decreases.

FIG. 15 shows the relationship between the bump electrode height and the connection resistance value.

In the figure, the curve n ₂ represents the result for the electronic circuit device manufactured in the same manner as in Example II-1. The curve o ₂ represents the result when a through hole is formed in the bump portion of the same mounting resin sheet, and further, the curve p
₂ shows the result when the solder as the metal conductor is embedded in the through hole provided in the resin sheet.

As shown in FIG. 15, when a resin sheet having no through hole is used (curve n ₂ ), it is 25
Even with bumps with a height of mm, the connection resistance value is nearly an order of magnitude larger,
The connection resistance value further increases as the bump electrode height increases. When a resin sheet having a through hole is used (curve o ₂ ), the resistance value at a height of 25 mm is small, but as the bump electrode height increases, the resistance value increases similarly to the case of the curve n ₂ described above. . When a resin sheet in which a metal conductor is embedded in the through hole is used (curve p ₂ ), the connection resistance value shows a constant value with almost no increase.

From the above results, by using the resin sheet having through holes at the positions corresponding to the bump electrodes,
It can be seen that even if the number of bump electrodes and the bump height increase, the bump electrodes and the electrode pads of the circuit wiring board can be connected more reliably. Further, by embedding the metal conductor in the through hole provided in the resin sheet, the electrical connection can be made more reliable.

[0229]

As described in detail above, according to the present invention,
Provided is a BGA package in which warpage of a substrate is prevented by sealing with a resin having a very small elastic modulus after molding or by using a resin sheet having a shrinkage prevention plate attached to one surface. To be done. When such a package is mounted on a circuit board, it is possible to obtain an electronic circuit device with improved reliability of the connecting portion.

Further, by disposing resin sheets having stepwise different thermal expansion coefficients in the thickness direction in the gap between the BGA package and the circuit wiring board, stress strain generated in the bump connection portion of the electronic circuit device can be reduced. It can be relaxed and the reliability life can be improved.

Such a package and electronic circuit device are
It is applicable to various devices and its industrial value is enormous.

[Brief description of drawings]

FIG. 1 is a sectional view showing an example of a manufacturing process of a resin-encapsulated semiconductor device of the present invention.

FIG. 2A is a diagram showing a mechanical combination model diagram of elasticity and viscosity. (B) The figure which shows the phase relationship of stress amplitude and strain amplitude.

FIG. 3 is a diagram showing a warp of a package.

FIG. 4 is a cross-sectional view showing another example of the manufacturing process of the resin-encapsulated semiconductor device of the present invention.

FIG. 5 is a sectional view showing an example of a manufacturing process of the electronic circuit device of the present invention.

FIG. 6 is a sectional view showing a BGA package and a circuit wiring board used in the electronic circuit device of the present invention.

FIG. 7 is a diagram showing a resin sheet used in the electronic circuit device of the present invention.

FIG. 8 is a cross-sectional view showing the manufacturing process of the electronic circuit device of the present invention.

FIG. 9 is a cross-sectional view showing the manufacturing process of the electronic circuit device of the present invention.

FIG. 10 is a diagram showing another example of the electronic circuit device of the present invention.

FIG. 11 is a diagram showing the relationship between the number of cycles and the cumulative defective rate.

FIG. 12 is a diagram showing the relationship between the dimensions of a resin sheet and the number of fatigue life cycles.

FIG. 13 is a diagram showing the relationship between the package size and the number of fatigue life cycles.

FIG. 14 is a diagram showing a relationship between the number of connection bumps and a bump connection rate.

FIG. 15 is a diagram showing the relationship between bump height and connection resistance value.

FIG. 16 is a diagram showing a conventional electronic circuit device.

[Explanation of symbols]

1 ... Ball grid array substrate, 2 ... Solder terminal, 3 ...
Semiconductor chip 4 ... Bonding wire, 5 ... Sealing resin sheet, 6 ...
Mounting resin sheet 7 ... Outer mold, 8 ... Inner mold, 9 ... Upper mold, 10 ... Lower mold 11 ... Shrinkage prevention plate, 12 ... Circuit board, 13 ... Sealing resin,
14 ... Solder pad 21 ... Ball grid array package, 22 ... Package substrate 23 ... Semiconductor chip, 25 ... Bump electrode, 26 ... Resin cap 27 ... Bonding wire, 28 ... Circuit wiring board, 29
... Electrode pad 30 ... Resin sheet, 32 ... Heating heater 33 ... Package mounting mounter head, 34 ... Pressurizing heater 40 ... Resin sheet, 41 ... Through hole, 42 ... Resin sheet,
43 ... Metal conductor 51 ... Circuit wiring board, 52 ... Semiconductor chip, 53 ... Bump, 54 ... Resin.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification number Internal reference number FI technical display location 9169-4M H01L 21/92 604 H (72) Inventor Akira Zensaku Komukai Toshiba, Kawasaki City, Kanagawa Prefecture Town No. 1 Incorporated company Toshiba Research and Development Center (72) Inventor Hiroshi Yamada No. 33 Shinisogo-cho, Isogo-ku, Yokohama-shi, Kanagawa Incorporated company Toshiba Production Engineering Laboratory

Claims (9)

[Claims] 1. A substrate, a semiconductor element arranged on the surface of the substrate, and a resin layer for sealing the semiconductor element, wherein the resin layer is arranged only on the side on which the semiconductor element is arranged with respect to the substrate. In the resin-encapsulated semiconductor device, the resin-encapsulated semiconductor device includes a step of disposing a semiconductor element on a substrate, a step of disposing a sheet-shaped uncured resin on the semiconductor element, and a resin sheet in a mold. And the resin layer has a complex elastic modulus of 6.5 × 10 ⁹ at room temperature after molding.
A resin-encapsulated semiconductor device, which is Pa or less and has a mechanical tangent loss Tan δ of 0.05 or more. 2. The resin-sealed semiconductor device according to claim 1, wherein spherical solder bumps for input / output terminals are two-dimensionally arranged on the back surface of the substrate. 3. The resin-encapsulated semiconductor device according to claim 1, wherein a rubber component is contained in the organic component of the encapsulating resin layer in an amount of 5% or more. 4. A substrate having a two-dimensionally arranged solder bumps for input / output terminals on a back surface thereof, and a semiconductor element mounted on the surface of the substrate, wherein the surface of the substrate on which the semiconductor element is mounted is provided. A resin-encapsulated semiconductor device, which is encapsulated with a resin sheet having a shrinkage-prevention plate attached to one surface thereof. 5. A package substrate having solder bumps for input / output terminals arranged two-dimensionally on a back surface thereof, and a semiconductor package including a semiconductor element mounted on the surface of the substrate,
An electronic circuit device comprising a circuit wiring board for connecting and mounting the package, wherein a thermosetting resin having a thermal expansion coefficient gradually different in a thickness direction in a gap between the package board and the circuit wiring board. An electronic circuit device having a sheet arranged. 6. The electronic circuit device according to claim 5, wherein the thermosetting resin sheet arranged in the gap has a vertical and horizontal dimension that is 20 to 40% larger than a vertical and horizontal dimension of the package substrate. 7. The electronic circuit device according to claim 5, wherein the resin sheet has through holes formed at positions corresponding to bump electrodes formed two-dimensionally on the back surface of the package substrate. 8. The electronic circuit device according to claim 7, wherein a metal conductor is embedded in a through hole provided in the resin sheet. 9. A step of placing an uncured thermosetting resin sheet having a different thermal expansion coefficient in the thickness direction while applying pressure on a circuit wiring board having an electrode pad formed on the front surface, and input / output on the back surface. A semiconductor package including a package board in which solder bumps for terminals are two-dimensionally arranged and a semiconductor element mounted on the surface of the package board are provided so that the solder bumps correspond to the electrode pads of the circuit wiring board. Step of aligning and mounting on a sheet, by applying heat and pressure in a mold to a circuit wiring board on which a semiconductor package is mounted via the resin sheet, the resin sheet is softened and The process of bringing the solder bump into contact with the corresponding electrode pad and further increasing the heat and pressure melts the solder. While the electrode pad and the bump electrodes of the road-wiring board are electrically connected, a method of manufacturing an electronic circuit device according to at least comprising the step of curing the resin sheet.