TWI659975B - Phenol resin, epoxy resin composition containing the phenol resin, cured product of the epoxy resin composition, and semiconductor device having the cured product - Google Patents

Abstract

The phenol resin of the present invention is represented by the general formula (1). The phenol resin is one which imparts a thermal expansion coefficient of 40% or higher and 180 ° C or lower to a cured product obtained from the phenol resin, the epoxy resin represented by the general formula (2), and the curing accelerator. The phenol resin is preferably one which imparts a storage elastic modulus of 15 MPa or more at 250 ° C to the cured product. It is also preferable that R in the general formula (1) is an allyl group, p is 1 or 2, and q is 1 or 2. It is also preferable that the phenol resin has a softening point of 60 ° C or higher and 90 ° C or lower.

(In the formula, R represents a saturated or unsaturated aliphatic hydrocarbon group having a carbon number of 2 to 15 and may be the same or different; q represents an integer of 1 to 3 and may be the same or different; p represents 1 or 2, can be the same or different; n represents an integer above 0)

Description

Phenol resin, epoxy resin composition containing the phenol resin, cured product of the epoxy resin composition, and semiconductor device having the cured product

The present invention relates to a phenol resin. The present invention also relates to an epoxy resin composition containing the phenol resin and a cured product of the epoxy resin composition. Furthermore, this invention relates to the semiconductor device which has this hardened | cured material.

Epoxy resin compositions are widely used in electrical, electronic parts, materials for construction, adhesives, coatings, etc. due to their excellent electrical properties, heat resistance, adhesion, and moisture resistance.

In recent years, along with the high performance, miniaturization, and thinness of electronic devices such as smart phones and tablet terminals, the multi-pin, high-integration, miniaturization, and thinness of semiconductor devices are being accelerated. Therefore, with regard to single-sided sealed packages such as BGA (Ball Grid Array) packages, it is required to improve reliability by reducing warpage accompanying thinning.

In the single-sided hermetic package, there is a problem that internal stress remains due to a difference in thermal expansion coefficient between a substrate material and a member used in a semiconductor device typified by a sealing resin, so warpage occurs and mounting reliability decreases. In the previous single-sided sealed package, the thermal expansion rate of the sealing resin is larger than that of a substrate material including a substrate such as glass cloth, and warpage occurs on the sealing resin side. Therefore, the low thermal expansion rate of the sealing resin has been continuously reduced. the study.

However, in recent years, single-sided sealed packages are being thinned, and packages with thinner sealing resin layers have increased. Therefore, unlike previous single-sided hermetic packages, Due to the shrinkage of the substrate material, a problem of warpage occurs on the substrate material side. Therefore, it is urgent to reduce the warpage to the substrate material side at room temperature by increasing the heat shrinkage of the sealing resin after molding.

As a method for reducing the warpage by increasing the heat shrinkage of the sealing resin, there have been proposed methods for improving the heat shrinkage rate by reducing the amount of the inorganic filler in the sealing resin (Patent Document 1), or By using a polysiloxane containing a silanol group without containing an alkoxy group of silicon directly bonded to the polysiloxane, the heat shrinkage rate of the sealing resin is improved (Patent Document 2).

In addition, as the thickness of the sealing resin becomes thinner, there is an urgent need to improve reliability by applying rigidity when heat is applied to the sealing resin. Therefore, materials with higher rigidity under heat, that is, higher modulus of elasticity under heat are also urgently required.

Prior art literature Patent literature

Patent Document 1: Japanese Patent Laid-Open No. 8-153831

Patent Document 2: Japanese Patent Laid-Open No. 2013-224400

However, if the amount of the inorganic filler is reduced as in the technique described in Patent Document 1, there is a concern that the moisture resistance reliability may be deteriorated due to the deterioration of the water absorption of the cured product. Moreover, even if the silanol group-containing polysiloxane compound described in Patent Document 2 is used, the elastic modulus of the cured product is not improved. Thus, the technology proposed so far focuses on the additives in the epoxy resin composition, and there is no proposal for improving the resin itself. Therefore, it is desired to develop a phenol resin that has a large thermal expansion when heating the hardened material of the epoxy resin composition, that is, a large thermal contraction when cooling, and a high elastic modulus when thermal.

Therefore, an object of the present invention is to provide a phenol resin, which can obtain an epoxy resin combination with high heat shrinkage and elastic modulus at high heat, which can improve reliability by reducing warpage of a thin, single-sided sealed package. Thing.

In order to solve the above-mentioned problems, the present inventors worked hard and found that the heat shrinkage rate of the hardened material having a large degree of thermal expansion generated by heating also increased during cooling. Based on this knowledge, further research was conducted, and it was found that: By using a phenol resin containing a phenol compound having a saturated or unsaturated hydrocarbon group having 2 or more and 15 or less carbon atoms, an epoxy resin combination having a large degree of thermal expansion by heating and a high thermal shrinkage rate upon cooling can be obtained Material and hardened material to complete the present invention.

That is, the present invention solves the above-mentioned problems by providing a phenol resin represented by the following general formula (1),

(In the formula, R represents a saturated or unsaturated aliphatic hydrocarbon group having a carbon number of 2 to 15 and may be the same or different; q represents an integer of 1 to 3 and may be the same or different; p represents 1 or 2, can be the same or different; n represents an integer above 0)

The phenol resin pair consists of the phenol resin and the following general formula (2)

The hardened | cured material obtained from the said epoxy resin and hardening accelerator has a thermal expansion coefficient of 1.5% or more from 40 degreeC or more and 180 degreeC or less.

The present invention also provides an epoxy resin composition including the phenol resin and an epoxy resin, and an epoxy resin hardened product obtained by curing the epoxy resin composition.

Has a seal formed from an epoxy resin composition using the phenol resin of the present invention Due to the high thermal expansion rate of the sealing material when it is heated, the thermal contraction rate of the semiconductor device with a thin single-sided hermetically sealed package is also high, thereby reducing the amount of heat generated by the substrate material on which the semiconductor device is mounted. Warping.

The phenol resin of the present invention is represented by the general formula (1). In the formula (1), the saturated or unsaturated hydrocarbon group represented by R is one having a large free volume of rotation around the phenylene axis, from the viewpoint of exhibiting high thermal expansion properties upon heating and further high thermal shrinkage properties upon cooling. From this viewpoint, as described above, the carbon number of R is 2 or more and 15 or less, preferably 3 or more and 15 or less, still more preferably 3 or more and 10 or less, and most preferably 3 or 4.

When R is a saturated hydrocarbon group in the formula (1), examples of the group include an ethyl group, an n-butyl group, a third butyl group, a propyl group, and an octyl group. It is particularly preferred to use a third butyl group as a base having a large free volume of rotation around the phenylene axis. On the other hand, when R is an unsaturated hydrocarbon group, examples of the group include allyl, 1-propenyl, and ethynyl. In particular, if an allyl group is used as a base with a large free volume of rotation around the phenylene axis, the thermal expansion rate of the hardened material of the epoxy resin composition can be increased, and the elastic modulus at thermal time can be increased, which is preferable. . R may be the same or different. It is preferred that all of R be the same base. In this case, the group is preferably allyl.

In the formula (1), as described above, q represents an integer of 1 or more and 3 or less, and preferably 1 or 2. In order to increase the thermal modulus of elasticity of the cured epoxy resin, the value of q is preferably larger. Moreover, in Formula (1), it is preferable that p is either 1 or 2. When p and q are both 1, R is preferably bonded to the ortho or para position with respect to OH.

In the formula (1), as described above, n represents an integer of 0 or more. The upper limit of n is preferably a value at which the melt viscosity of the phenol resin of the present invention at 150 ° C becomes 30.0P or less, more preferably 0.1P or more and less than 20.0P, and more preferably 0.1P or more. And below 10.0P, The value is more preferably 0.1P or more and 7.0P or less, and most preferably 0.1P or more and 5.0P or less. The phenol resin of the present invention is an aggregate of polymers having various molecular weights, so the value of n is represented by the average value of the aggregate.

The phenol resin of the present invention preferably has a melt viscosity at 150 ° C. in the above-mentioned range in that a semiconductor sealing material obtained by kneading with an inorganic filler or the like can be smoothly manufactured. Further, in terms of operability in processing such as adhesion, or operability in kneading work with an inorganic filler, etc., it is preferable that the softening point is a temperature lower than 25 ° C (that is, at 25 ° C it is Liquid state) to 100 ° C or lower, particularly 50 ° C or higher and 100 ° C or lower, especially 60 ° C or higher and 90 ° C or lower, especially 60 ° C or higher and 80 ° C or lower. Moreover, it is also preferable from the point which can raise the thermal modulus of the epoxy resin hardened | cured material obtained from the phenol resin of this invention. Furthermore, from the viewpoint of effectively preventing an excessive decrease in the crosslinking density of the epoxy resin cured product and effectively suppressing a decrease in the elastic modulus under heat, the hydroxyl equivalent thereof is preferably 400 g / eq or less, particularly 300 g. / eq or less, especially 200 g / eq or less. The lower limit of the hydroxyl equivalent is not particularly limited, and as long as it is 100 g / eq or more, satisfactory results can be obtained. The methods for measuring these physical properties are described in the following examples.

The phenol resin of the present invention imparts a cured product obtained from the epoxy resin and the hardening accelerator represented by the general formula (2) to a temperature of 40 ° C. or higher and 180 ° C. or lower by 1.5% or more, preferably 1.55% or more, and more preferably A higher thermal expansion rate of 1.60% or more, more preferably 1.65% or more, and most preferably 2.00% or more, in other words, a higher thermal shrinkage rate during cooling. If a thin single-sided hermetically sealed semiconductor device is manufactured by using a sealing material containing a hardening agent having such a thermal expansion coefficient, the sealing material has a high thermal expansion ratio, that is, a high thermal shrinkage ratio during cooling, which can be reduced to Warpage caused by a substrate material on which a semiconductor device is mounted.

From the viewpoint that the effect of reducing the warpage is more significant, the phenol resin of the present invention preferably gives a cured product obtained by the epoxy resin and the hardening accelerator represented by the general formula (2) at 250 ° C. Those with a storage elastic modulus of 15 MPa or more. Make it warp From the viewpoint that the reduction effect is further more significant, the phenol resin of the present invention is more preferably one which imparts a storage elastic modulus of 15 MPa or more and 120 MPa or less, especially 30 MPa or more and 110 MPa or less, especially 80 MPa or more and 100 MPa or less.

The method for measuring the thermal expansion coefficient and the storage elastic modulus is described in the following examples.

The phenol resin of the present invention can be obtained by reacting a phenol compound represented by the following general formula (3) with formaldehyde under an acidic catalyst or a basic catalyst.

(Where R, q and p are the same as defined above)

Examples of the phenol compound represented by the formula (3) are not particularly limited, and examples thereof include ethylphenol, propylphenol, n-butylphenol, third butylphenol, octylphenol, allylphenol, and diphenol. Propylphenol, dibutylphenol, etc. These phenol compounds may be used alone or in combination of two or more. In particular, in terms of increasing the thermal expansion rate of the hardened material obtained from the phenol resin of the present invention during heating and increasing the thermal shrinkage rate during cooling, it is preferable to use allylphenol or third butylphenol, and it is particularly preferred To use o-allylphenol.

The form of formaldehyde, which is a compound that forms a methylene crosslinking group between the compounds represented by formula (3), is not particularly limited. For example, formaldehyde can be used in the form of an aqueous solution. Or also paraformaldehyde or three Alkane is used in the form of a polymer which is decomposed in the presence of an acid to generate formaldehyde.

The preferred phenol resin of the present invention is more advantageous in terms of shortening the gelation time of the epoxy resin composition and improving the thermal expansion rate of the cured epoxy resin. It is preferably a narrow-dispersion type having a small amount of low molecular weight components. In particular, in terms of further shortening the gelation time and achieving a high thermal expansion coefficient, it is preferred that n = 0 in the general formula (1) have fewer compounds. From this point of view, based on the area ratio of the graph obtained based on the gel permeation chromatography of the phenol resin of the present invention, the compound of n = 0 in the general formula (1) is based on the entire phenol resin, It is preferably 5.5 area% or less, and more preferably 4.5 area% or less. The lower limit value of the ratio of the compound of n = 0 to the entire phenol resin is not particularly limited, and the smaller the better, the most preferable being 0.

In addition, in terms of reducing the gelation time of the epoxy resin composition and improving the thermal modulus of the epoxy resin hardened product, n = The total content of the compound of 0 and the compound of n = 1 is 10.0 area% or less, and more preferably 7.0 area% or less. The lower limit of the ratio of the compound of n = 0 and the compound of n = 1 to the entire phenol resin is not particularly limited. In terms of improving the elastic modulus at thermal time, it is preferably 4.0% by area or more, and more preferably It is 4.5 area% or more.

In addition, in terms of reducing the gelation time of the epoxy resin composition and improving the thermal modulus of the epoxy resin hardened product, n = The content of the compound of 2 is 4.0 area% or more and 14.0 area% or less, and more preferably 5.0 area% or more and 13.5 area% or less.

By setting the total content of the compound of n = 0 and the compound of n = 1 in the general formula (1) and the content of the compound of n = 2 in the general formula (1) to the above ranges, the molecular weight distribution and molecular weight can be obtained. A narrowly dispersed phenol resin with a better balance can set the softening point of the phenol resin and the melt viscosity at 150 ° C to a better range, which can shorten the gelation time of the epoxy resin composition and improve the hardening of the epoxy resin. The thermal expansion rate of the material increases the elastic modulus under heat. For example, when the total content of the compound of n = 0 and the compound of n = 1 is less than 4.0 area% and the content of the compound of n = 2 is less than 4.0 area%, the compound having a molecular weight higher than that of the compound of n = 2 The content of (n = 3 or more compounds) is increased and the polymer is quantified. Therefore, the softening point and the melting viscosity at 150 ° C may be excessively increased. Also, even if n = When the total content of the compound of 0 and the compound of n = 1 is 10.0 area% or less, and when the content of the compound of n = 2 is greater than 14.0 area%, the molecular weight also decreases, so there is a softening point and melting at 150 ° C When the viscosity is excessively reduced.

The weight average molecular weight of the preferred phenol resin of the present invention is not particularly limited, but is preferably 1,000 or more and 8,000 or less, more preferably 1400 or more and 4,000 or less, and further preferably 1,500 or more and 3,000 or less. The value of the weight average molecular weight / number average molecular weight as the degree of dispersion of the molecular weight distribution is preferably 1.0 or more and 4.0 or less, more preferably 1.3 or more and 2.5 or less, and still more preferably 1.4 or more and 2.0 or less. In addition, by setting both the weight average molecular weight and the degree of dispersion to the above ranges, the gelation time of the epoxy resin composition can be shortened, and at the same time, the thermal expansion coefficient of the cured epoxy resin can be increased and the elastic modulus at thermal time can be improved.

The phenol resin of the present invention can be obtained by using the phenol compound and formaldehyde as raw materials in the presence of an acidic catalyst or a basic catalyst. As the usable catalyst, when it is an acidic catalyst, for example, oxalic acid, sulfuric acid, p-toluenesulfonic acid and the like can be cited. In the case of a basic catalyst, examples thereof include alkali metal catalysts such as sodium hydroxide and potassium hydroxide, ammonia, and amine catalysts such as triethylamine. It is particularly preferable to use an acid catalyst such as oxalic acid, sulfuric acid, and p-toluenesulfonic acid. In particular, in terms of catalyst removal efficiency, oxalic acid is preferably used. In particular, the above-mentioned narrow-dispersion type phenol resin can be preferably prepared by, for example, the following production method, but it is not limited. The production method includes a first step of making the phenol represented by the general formula (3) The compound and formaldehyde undergo a soluble phenolylation reaction in the presence of a basic catalyst; and in the second step, a phenol compound represented by the general formula (3) is added to the reaction mixture obtained in the first step, and The novolak reaction is performed in the presence of an acid catalyst. In this preparation method, the ratio of the components of the i component (i represents the component of n = i in the general formula (1)) in the phenol resin can be determined by changing the ratio of the reaction raw materials, the reaction time, and the reaction temperature to the following: The illustrated method is adjusted for easy control. Furthermore, by carrying out preliminary tests as necessary, the operator can accurately determine the actual reaction conditions.

The first step in the above production method will be described.

Regarding the ratio of the phenol compound represented by the general formula (3) and formaldehyde reacted in the first step, the formaldehyde is preferably 1 to 3 moles, more preferably 1 to 3 moles relative to the phenol compound represented by the general formula (3). It is 1.5 to 2.5 moles. By setting the ratio of the phenol compound to formaldehyde within this range, the generation of low-molecular-weight components can be suppressed, and the generation of high-molecular-weight components can also be suppressed, and a narrowly dispersed phenol resin can be obtained.

The use amount of the alkaline catalyst in the first step is not limited, and it is preferably a ratio of 0.1 to 1.5 mol, more preferably 0.2 to 1.0 mol, relative to 1 mol of the phenol compound represented by the general formula (3). Ear ratio. By using an alkaline catalyst at this ratio, the reaction proceeds smoothly, unreacted components are less likely to remain, and the catalyst is easily removed, resulting in improved productivity. The reaction temperature is not limited, but is preferably 10 to 80 ° C, and more preferably 20 to 60 ° C. By setting the reaction temperature within this range, the reaction proceeds smoothly, and the generation of high-molecular-weight components can be suppressed, making it easy to control the soluble phenol-formaldehyde reaction. The reaction time is not limited, but is preferably 0.5 to 24 hours, and more preferably 3 to 12 hours.

Next, the second step will be described.

In the second step, it is preferable to neutralize the reaction mixture obtained in the first step with the soluble phenol-formaldehyde reaction with an acidic compound, and then add the phenol compound represented by the general formula (3), and further add an acidic catalyst. Media. Examples of the acidic compound used for neutralization include hydrochloric acid, sulfuric acid, phosphoric acid, formic acid, acetic acid, oxalic acid, butyric acid, lactic acid, benzenesulfonic acid, and p-toluenesulfonic acid. The acidic compound may be used singly or in combination of two or more kinds.

The phenol compound represented by the general formula (3) used in the second step is preferably 0.5 to 1.5 mol, more preferably the phenol compound represented by the general formula (3) used in the first step. It is preferably 0.7 to 1.1 mol. By setting the used amount of the phenol compound represented by the general formula (3) used in the second step to this range, the generation of high molecular weight components can be suppressed, and the melt viscosity of the phenol resin can be suppressed from being excessively increased due to this. In addition, unreacted phenols are less likely to remain.

The amount of the acidic catalyst used in the second step is preferably a ratio of 0.0001 to 0.07 mol, and more preferably, relative to 1 mol of the phenols represented by the general formula (3) used in the first step. 0.0005 ~ 0.05 mole. By using an acidic catalyst within the range of this ratio, the reaction can proceed smoothly, and the generation of high molecular weight components can be suppressed, making it easy to control the reaction. The reaction temperature is not limited, but is preferably about 50 to 150 ° C, more preferably about 80 to 120 ° C, and even more preferably about 70 to 100 ° C. By setting it within this temperature range, the reaction can proceed smoothly, and the generation of high molecular weight components can be suppressed, making it easy to control the novolac reaction. The reaction time is not limited, but is preferably 0.5 to 12 hours, and more preferably 1 to 6 hours. By setting the reaction time within this range, the reaction can proceed smoothly and the generation of high molecular weight components can be suppressed. Examples of the acidic catalyst used in the second step include the same as the acidic compound used in the step.

Next, the epoxy resin composition of this invention containing the said phenol resin is demonstrated. The epoxy resin used in the epoxy resin composition of the present invention is not particularly limited, and examples thereof include bisphenol A epoxy resin, bisphenol F epoxy resin, and phenol aralkyl epoxy resin. Glycidyl ether epoxy resin, glycidyl ester epoxy resin, etc., cresol novolac epoxy resin, phenol novolac epoxy resin, triphenol methane epoxy resin, biphenyl epoxy resin, etc. Glycerylamine-type epoxy resins, halogenated epoxy resins, and other epoxy resins having two or more epoxy groups in the molecule. These epoxy resins may be used alone or in combination of two or more. A particularly preferred epoxy resin is the biphenyl epoxy resin represented by the general formula (2) described above.

Regarding the addition ratio of the epoxy resin used in the epoxy resin composition of the present invention, it is preferably a ratio of the hydroxyl equivalent (g / eq) of the phenol resin represented by formula (1) to the epoxy equivalent in the epoxy resin. The ratio, that is, the value of hydroxyl equivalent / epoxy equivalent is in a range of 0.5 or more and 2.0 or less, and more preferably in a range of 0.8 or more and 1.2 or less. By setting the value of the hydroxyl equivalent / epoxy equivalent within this range, the curing reaction can proceed sufficiently, and unreacted curing agent or epoxy resin can be effectively prevented from remaining. Thereby, a high thermal expansion coefficient can be obtained during heating, Further, a hardened material having a high thermal shrinkage rate upon cooling.

The phenol resin represented by formula (1) functions as a hardener for epoxy resin in the epoxy resin composition of the present invention, but the epoxy resin composition of the present invention may also include a phenol resin represented by formula (1) Other hardeners. The type of the hardener other than the phenol resin represented by the formula (1) is not particularly limited, and various hardeners can be used according to the purpose of use of the epoxy resin composition. For example, an amine-based hardener, an amine-based hardener, an acid anhydride-based hardener, and the like can be used.

In the epoxy resin composition of the present invention, the proportion of the phenol resin represented by formula (1) in all the hardeners sufficiently improves the high expansion property of the hardened material obtained from the epoxy resin composition upon heating, From the viewpoint of sufficiently improving the high heat shrinkability during cooling, a higher ratio is preferred. Specifically, the proportion of the phenol resin represented by formula (1) in all the hardeners is preferably 30% by mass or more, more preferably 50% by mass or more, still more preferably 70% by mass or more, and even more preferably 90% by mass, particularly preferably 100% by mass.

In the epoxy resin composition of the present invention, other components used in a general epoxy resin composition can be preferably used according to its application. For example, a hardening accelerator for hardening an epoxy resin with a phenol resin can be used. Examples of the hardening accelerator include well-known organic phosphine compounds and their boron salts, tertiary amines, quaternary ammonium salts, imidazoles and their tetraphenyl boron salts. Among these, triphenylphosphine is preferably used from the viewpoint of hardenability or moisture resistance. Furthermore, when a further high fluidity is required for the epoxy resin composition, it is preferred to use a hardening accelerator that exhibits thermal latent properties by heat treatment. Examples of such a hardening accelerator include tetraphenylphosphonium derivatives such as tetraphenylphosphonium tetraphenylborate. The addition ratio of a hardening accelerator to an epoxy resin composition can be made the same as the ratio in a well-known epoxy resin composition.

In the epoxy resin composition of the present invention, a filler such as an inorganic filler can be further preferably blended. As the inorganic filler, for example, amorphous silicon dioxide, crystalline silicon dioxide, aluminum oxide, calcium silicate, calcium carbonate, talc, mica, and barium sulfate can be used. Youjia It uses amorphous silicon dioxide and crystalline silicon dioxide. The particle diameter of the inorganic filler is not particularly limited, and considering the filling ratio, it is more preferably from 0.01 μm to 150 μm. The blending ratio of the inorganic filler is not particularly limited, and the ratio of the inorganic filler in the epoxy resin composition is preferably 70% by mass or more and 95% by mass or less, and more preferably 70% by mass or more and 90% by mass or less. the following. By setting the blending ratio of the inorganic filler to this range, the water absorption of the cured product of the epoxy resin composition is less likely to increase, so it is preferable. In addition, the thermal expansion property of the hardened material during heating is sufficiently increased, and thereby the thermal shrinkage property during cooling is sufficiently increased, and the fluidity is not easily impaired, which is preferable.

In the epoxy resin composition of the present invention, a release agent, a coloring agent, a coupling agent, a flame retardant, or the like may be further added as necessary or used in advance. The blending ratio of these additives may be the same as the ratio in the known epoxy resin composition. In the epoxy resin composition of the present invention, if necessary, nitrogen-based flame retardants such as melamine and isocyanuric acid compounds, and phosphorus-based flame retardants such as red phosphorus, phosphoric acid compounds, and organic phosphorus compounds may be appropriately added as the flame retardants. Flame retardant additives.

When preparing the epoxy resin composition of the present invention, for example, a phenol resin, an epoxy resin, and a hardening accelerator, an inorganic filler, and other additives added as necessary are uniformly mixed using a stirrer or the like, and a heating roller or a kneader is used A kneading machine such as an extruder is kneaded in a molten state, the kneaded material is cooled, and pulverization may be performed as necessary.

The epoxy resin composition obtained in this way can be preferably used as a sealing material for sealing a semiconductor element, but it is not particularly limited. For example, the lead frame or the like on which the semiconductor element is mounted can be placed in a metal mold cavity, and then the epoxy resin composition can be formed by a molding method such as transfer injection molding, compression molding, or injection molding. The semiconductor device is preferably obtained by subjecting the epoxy resin composition to heat treatment at a temperature or the like. Especially when the semiconductor device includes a thin single-sided sealed package, the cured product of the epoxy resin composition has a high expansion property, so that the cured product shrinks significantly when it is cooled, thereby exerting an effect of effectively reducing warpage. Beneficial effects.

Examples

Hereinafter, the present invention will be specifically described with reference to examples. However, the scope of the present invention is not limited to these examples. Unless otherwise specified, "part" means "mass part". "%" Means "mass%".

[1] Preparation of phenol resin

An analysis method and an evaluation method used in the following preparation examples of the phenol resin will be described.

<Softening point> It is calculated | required by measuring the softening point of the ring and ball method based on JIS K6910.

<150 ° C Melt Viscosity> The melt viscosity of phenol resin and epoxy resin at 150 ° C was measured using an ICI (Imperial Chemical Industries, British Empire Chemical Industry Corporation) melt viscosity meter.

The measuring method of ICI viscosity is as follows.

ICI Cone and Plate Viscometer Model CV-1S TOA Industrial Co., Ltd.

The plate temperature of the ICI viscometer was set to 150 ° C, and a specific amount of sample was weighed. Place the weighed resin on the plate and press it with a cone from the top for 90 seconds. The cone is rotated and its torque value is read as the ICI viscosity.

<Hydroxy equivalent> It calculated | required by the hydroxyl equivalent measurement based on JISK0070.

<Measurement of molecular weight distribution> The molecular weight distribution of a phenol resin was measured by a gel permeation chromatography measurement as follows. The ratio of the i component (i is a component of n = i in the general formula (1)) in the phenol resin was calculated based on the peak area of the measured graph using the analysis software Multi Station GPC-8020. At this time, the straight line before and after the peak is set as a reference line (zero value), and the peaks of each component are divided by the vertical cut at the lowest point. The sampling interval is set to 500 milliseconds. The molecular weight (Mw, Mn) and the degree of dispersion (Mw / Mn) are calculated by standard polystyrene conversion.

Device: HLC-8220 (manufactured by Tosoh Co., Ltd., gel permeation chromatography analysis device)

Tubing: TSK-GEL H type

G2000H × L 4

G3000H × L 1

G4000H × L 1

Measurement conditions: column pressure 13.5MPa

Solution: Tetrahydrofuran (THF)

Flow rate: 1mL / min

Measurement temperature: 40 ° C

Detector: RI (Refractive index) detection unit

Range (RANGE): 256 (Recorder output: 256 × 10 ^-6 RIU / 10mV)

Temperature control (temperature adjustment temperature of RI optical block): 40 ℃

Injection volume: 100μmL

Sample concentration: 5mg / mL (THF)

<Measurement of Molecular Weight (Mw, Mn) and Dispersion (Mw / Mn)> The molecular weight (Mw, Mn) and dispersion (Mw / Mn) of the phenol resin were measured by gel permeation chromatography in the following manner. . The ratio of the i component (i is a component of n = i in the general formula (1)) in the phenol resin was calculated based on the peak area in the measured graph using the analysis software Multi Station GPC-8020. At this time, the straight line before and after the peak is set as a reference line (zero value), and the peaks of each component are divided by the vertical cut at the lowest point. The sampling interval is set to 500 milliseconds. The molecular weight (Mw, Mn) and the degree of dispersion (Mw / Mn) are calculated by standard polystyrene conversion.

Device: HLC-8220 (manufactured by Tosoh Co., Ltd., gel permeation chromatography analysis device)

Tubing: TSK-GEL H type

G2000H × L 4

G3000H × L 1

G4000H × L 1

Measurement conditions: column pressure 13.5MPa

Solution: Tetrahydrofuran (THF)

Flow rate: 1mL / min

Measurement temperature: 40 ° C

Detector: Spectrometer (UV-8020)

Range (RANGE): 2.56

Wavelength (WAVE LENGTH): 254nm

Injection volume: 100μmL

Sample concentration: 5mg / mL (THF)

<Gelation time>

Equipment: Automatic hardening time measuring device made by Cyber Corporation

Measurement conditions: 150 ℃ 600rpm

Measurement method: The epoxy equivalent of o-cresol type epoxy resin EOCN-1020-55 (manufactured by Nippon Kayaku Co., Ltd., epoxy equivalent: 195 g / eq) is equivalent to the hydroxyl equivalent of phenol resin (epoxy equivalent). The ratio to the hydroxyl equivalent is 1). Triphenylphosphine as a hardening accelerator is formulated at 1.9% relative to the epoxy resin, and the resulting epoxy resin composition is prepared as 50% methyl ethyl ketone (MEK ) Solution. The MEK solution of the epoxy resin composition was placed on a hot plate of a measuring device of about 0.6 mL for measurement. The time when the measured torque became 20% of the measurement upper limit torque value of the device was set as the gel time.

[Example 1]

134 parts (1.0 mol) of o-allylphenol, 32 parts (92 mol) of 92% paraformaldehyde, and 300 parts of a glass flask equipped with a thermometer, an addition, a distillation outlet, a cooler and a stirrer, 0.4 parts of pure water and 1.1 parts of oxalic acid. After refluxing at 100 ° C for 12 hours, and then at 160 ° C for 2 hours, it was cooled to 95 ° C. After cooling, 130 parts of pure water having a temperature of 90 ° C or higher was charged and washed with water. Thereafter, the internal temperature was raised to 160 ° C, and the pressure was reduced- The steam treatment removes unreacted components, thereby obtaining a phenol novolak resin A (a phenol novolak resin in which R in the general formula (1) is allyl, p = 1 and q = 1). The softening point of the obtained phenol novolak resin A was 73 ° C, the melt viscosity at 150 ° C was 4.3P, the hydroxyl equivalent was 170 g / eq, and the gelation time was 72 seconds. As measured by gel permeation chromatography, the compound with n = 0 is 5.9 area% of the entire phenol resin, and the compound with n = 1 is 6.2 area% of the entire phenol resin.

[Example 2]

134 parts (1.0 mol) of o-allylphenol, 36 parts (92 mol) of 92% paraformaldehyde, were placed in a glass flask with a capacity of 300 parts equipped with a thermometer, an addition, a distillation outlet, a cooler and a stirrer. 0.4 parts of pure water and 1.1 parts of oxalic acid. After refluxing at 100 ° C for 12 hours, and then at 160 ° C for 2 hours, it was cooled to 95 ° C. After cooling, 130 parts of pure water having a temperature of 90 ° C or higher was charged and washed with water. Thereafter, the internal temperature was raised to 160 ° C., and a reduced pressure-steam treatment was performed to remove unreacted components, thereby obtaining a phenol novolak resin B (where R in the general formula (1) is allyl, p = 1, q = 1 phenol novolac resin). The softening point of the obtained phenol novolak resin B was 98 ° C, the melt viscosity at 150 ° C was 20P, and the hydroxyl equivalent was 172 g / eq.

[Example 3]

2,000 parts of o-allylphenol (9.0 mol), 127 parts of 42% formalin (1.8 mol), and 2,000 parts of a glass flask equipped with a thermometer, an addition, a distillation outlet, a cooler and a stirrer, and 12 parts of oxalic acid. The reaction was carried out at 100 ° C for 7 hours under reflux. After completion of the reaction, 600 parts of pure water at 90 ° C or higher was added and washed with water. Thereafter, the internal temperature was raised to 160 ° C, and a reduced pressure-steam treatment was performed to remove unreacted components, thereby obtaining a phenol novolac resin C (where R in the general formula (1) is allyl, p = 1, q = 1 phenol novolac resin). The obtained phenol novolak resin C was liquid at normal temperature, and the hydroxyl equivalent was 141 g / eq.

[Example 4]

95 parts (0.5 mol) of diallyl resorcinol and 14 parts (42 mol) of 42% formalin were placed in a glass flask with a capacity of 300 parts equipped with a thermometer, addition, distillation outlet, cooler and mixer. ). After reacting at 100 ° C for 12 hours under reflux, it was cooled to 95 ° C. After cooling, 110 parts of pure water having a temperature of 90 ° C or higher was charged for washing. Thereafter, the internal temperature was raised to 160 ° C. and the pressure was reduced to obtain a phenol novolak resin D (a phenol novolak resin in which R in the general formula (1) is an allyl group and p = 2 and q = 2). The obtained phenol novolak resin D was liquid at normal temperature, and the hydroxyl equivalent was 108 g / eq.

[Example 5]

Into a glass flask with a capacity of 1,000 parts having a thermometer, an addition, a distillation outlet, a cooler, and a stirrer, put 200 parts of p-tert-butylphenol (1.3 mol), 42 parts of formalin 57 (0.8 mol), 0.3 parts of oxalic acid. After reacting at 100 ° C for 20 hours under reflux, it was cooled to 95 ° C. After cooling, 130 parts of pure water having a temperature of 90 ° C or higher was charged and washed with water. Thereafter, the internal temperature was raised to 180 ° C., and reduced pressure-steam treatment was performed to remove unreacted components, thereby obtaining a phenol novolac resin E (where R in the general formula (1) is a third butyl group, and p = 1. Phenol novolac resin with q = 1). The softening point of the obtained phenol novolak resin E was 99 ° C, the ICI viscosity at 150 ° C was 4.3P, and the hydroxyl equivalent was 167 g / eq.

[Example 6]

67.0 parts (0.50 mol) of o-allylphenol and 71.4 parts (42 mol) of formalin were charged into a glass flask with a capacity of 300 parts (300 mL) equipped with a thermometer, an addition, a distillation outlet, a cooler and a stirrer. ), And 19.2 parts (0.12 mole) of 25% sodium hydroxide as an alkaline catalyst, and reacted at 60 ° C. for 7 hours to perform the first step of the soluble phenolylation reaction. To this reaction mixture, 134 parts of pure water for stopping the reaction was added, the temperature was lowered to 40 ° C, and 17.5 parts (0.12 mol) of 25% hydrogen chloride was added for neutralization to obtain a reaction mixture. Then, 73.7 parts (0.55 moles) of o-allylphenol and 1.3 parts of oxalic acid as an acid catalyst were put into the reaction mixture, and the reaction was performed at 100 ° C for 2 hours, and then at 120 ° C for 2 hours to perform the second step. Step novolacization reaction. Reduce the temperature to 95 ° C and use pure water at this temperature 134 The obtained reaction mixture was washed with water. After washing with water, the temperature was increased to 160 ° C, and a reduced-pressure steam treatment was performed to remove unreactive components, thereby obtaining a phenol novolac resin I (where R in the general formula (1) is allyl, p = 1, q = 1 Phenol novolac resin). The softening point of the obtained phenol novolak resin I was 59 ° C, the ICI viscosity at 150 ° C was 1.2P, the hydroxyl equivalent was 154 g / eq, and the gelation time was 59 seconds. As measured by gel permeation chromatography, the compound with n = 0 is 3.5 area% of the entire phenol resin, and the compound with n = 1 is 6.0 area% of the entire phenol resin.

[Example 7]

67.0 parts (0.50 mol) of o-allylphenol, 71.4 parts (1.00 mol) of 42% formalin, and a glass flask with a capacity of 300 parts equipped with a thermometer, addition, distillation outlet, cooler and stirrer, and 19.2 parts (0.12 mole) of 25% sodium hydroxide as a basic catalyst was reacted at 60 ° C. for 7 hours to perform the first step of the soluble phenolylation reaction. To this reaction mixture, 134 parts of pure water for stopping the reaction was added, the temperature was lowered to 40 ° C, and 17.5 parts (0.12 mol) of 25% hydrogen chloride was added for neutralization to obtain a reaction mixture. Then, 60.3 parts (0.45 moles) of o-allylphenol and 1.3 parts of oxalic acid as an acid catalyst were put into the reaction mixture, and the reaction was performed at 100 ° C for 2 hours, and then at 120 ° C for 2 hours to perform the second step. Step novolacization reaction. Thereafter, in the same manner as in Example 6, a phenol novolak resin J (a phenol novolak resin in which R in the general formula (1) is allyl, p = 1 and q = 1) was obtained. The softening point of the obtained phenol novolak resin J was 74 ° C, the ICI viscosity at 150 ° C was 4.3P, the hydroxyl equivalent was 159 g / eq, and the gelation time was 55 seconds. As measured by gel permeation chromatography, the compound with n = 0 is 1.9 area% of the entire phenol resin, and the compound with n = 1 is 4.1 area% of the entire phenol resin.

[Example 8]

67.0 parts (0.50 mol) of o-allylphenol, 71.4 parts (1.00 mol) of 42% formalin, and a glass flask with a capacity of 300 parts equipped with a thermometer, addition, distillation outlet, cooler and stirrer, and 19.2 parts (0.12 mole) of 25% sodium hydroxide as alkaline catalyst, at 60 The reaction was carried out for 7 hours at a temperature of 7 ° C to perform the soluble phenol-formaldehyde reaction in the first step. To this reaction mixture, 134 parts of pure water for stopping the reaction was added, the temperature was lowered to 40 ° C, and 17.5 parts (0.12 mol) of 25% hydrogen chloride was added for neutralization to obtain a reaction mixture. Next, 46.9 parts (0.35 moles) of o-allylphenol and 1.3 parts of oxalic acid as an acid catalyst were added to the reaction mixture, and the reaction was performed at 100 ° C for 2 hours, and then at 120 ° C for 2 hours to perform the second step. Step novolacization reaction. Thereafter, in the same manner as in Example 6, a phenol novolak resin K (a phenol novolak resin in which R in the general formula (1) is allyl, p = 1 and q = 1) was obtained. The softening point of the obtained phenol novolak resin K was 91 ° C, the ICI viscosity at 150 ° C was 29P, the hydroxyl equivalent was 159 g / eq, and the gelation time was 51 seconds. As measured by gel permeation chromatography, the compound with n = 0 is 1.4 area% of the entire phenol resin, and the compound with n = 1 is 2.8 area% of the entire phenol resin.

[Comparative Example 1]

Into a glass flask having a capacity of 1,000 parts having a thermometer, an addition, a distillation outlet, a cooler, and a stirrer, 513 parts (5.5 mol) of phenol, 229 parts (3.3 mol) of 42% formalin, and 0.6 part of oxalic acid were placed. The reaction was carried out at 100 ° C for 6 hours under reflux. After completion of the reaction, the internal temperature was raised to 160 ° C, and a reduced pressure-steam treatment was performed to remove unreacted components, thereby obtaining a phenol novolak resin F (phenol of p = 1 and q = 0 in the general formula (1) Novolac resin). The softening point of the obtained phenol novolak resin F was 83 ° C, the ICI viscosity at 150 ° C was 2.0P, and the hydroxyl equivalent was 107 g / eq.

[Comparative Example 2]

Into a 300-capacity glass flask equipped with a thermometer, an addition, a distillation outlet, a cooler, and a stirrer, put 108 parts (1.0 mol) of o-cresol, 32 parts (0.98 mol) of 92% paraformaldehyde, and pure water. 0.4 parts and 1.1 parts of oxalic acid. Under reflux, the reaction was performed at 100 ° C for 6 hours, and further at 160 ° C for 2 hours. After the reaction is completed, a reduced pressure-steam treatment is performed to remove unreacted components, thereby obtaining a phenol novolak resin G (where R in the general formula (1) is a methyl group, and p = 1 and q = 1 are phenol novolak resins). ). Softening of the obtained phenol novolac resin G The point was 130 ° C, but the ICI viscosity at 150 ° C could not be measured. The hydroxyl equivalent was 116 g / eq.

[Comparative Example 3]

170 parts (1.0 mol) of o-phenylphenol, 42 parts (0.58 mol) of 42% formalin, and a glass flask with a capacity of 300 parts equipped with a thermometer, an addition, a distillation outlet, a cooler and a stirrer, and 3.8 parts of toluenesulfonic acid. After reacting at 100 ° C for 7 hours under reflux, it was cooled to 95 ° C. After cooling, it was neutralized with a 25% sodium hydroxide aqueous solution. Further, 340 parts of pure water at 90 ° C or higher was charged and washed with water. Thereafter, the internal temperature was raised to 160 ° C., and a reduced pressure-steam treatment was performed to remove unreacted components, thereby obtaining a phenol novolac resin H (where R in the general formula (1) is phenyl, p = 1, q = 1 phenol novolac resin). The softening point of the obtained phenol novolak resin H was 81 ° C, the ICI viscosity at 150 ° C was 1.7P, and the hydroxyl equivalent was 188 g / eq.

An epoxy resin composition was prepared using the phenol resins obtained in the examples and comparative examples, and the cured product characteristics of the cured product obtained from the epoxy resin composition were measured. These results are summarized and shown in Table 1.

[2] Preparation and evaluation of epoxy resin composition and hardened material

Using the phenol resins obtained in the examples and comparative examples, the biphenyl epoxy resin represented by the general formula (2) (manufactured by Mitsubishi Chemical Corporation, YX-4000, epoxy equivalent: 186 g / eq), And triphenylphosphine (produced by Beixing Chemical Co., Ltd., TPP) as a hardening accelerator to prepare an epoxy resin composition. In the preparation, the phenol resin and the epoxy resin were blended in such a manner that the ratio of the hydroxyl equivalent to the epoxy equivalent, that is, the value of [hydroxy equivalent (g / eq) / epoxy equivalent (g / eq)] became 1, and performed After heat-melting and mixing, triphenylphosphine was added in an amount shown in Table 1 and uniformly mixed to obtain an epoxy resin composition. The obtained epoxy resin composition was subjected to a post-curing treatment at 150 ° C. for 5 hours and a post-curing treatment at 180 ° C. for 8 hours to obtain a cured epoxy resin. The obtained hardened epoxy resin was measured for thermal expansion coefficient, glass transition point, linear expansion coefficient, and storage elastic modulus.

Analytical methods and evaluations used in the examples of the cured product of the epoxy resin composition The price method will be described.

(1) Storage elastic modulus

The epoxy cured product was cut out to 40 mm × 2 mm × 4 mm and set as a measurement sample. The measurement was performed using a dynamic viscoelasticity measuring device RSA-G2 manufactured by TA Instruments, and the storage elastic modulus was measured while increasing the temperature from 30 ° C at a heating rate of 3 ° C / min to obtain the storage elastic modulus at 250 ° C. The peak temperature of Tan δ is set to Tg.

(2) Glass transition temperature (Tg), coefficient of linear expansion (α1, α2) and thermal expansion coefficient

The epoxy cured product was cut out into a size of 10 mm × 6 mm × 4 mm and used as a measurement sample. The thermomechanical analysis device TMA-60 manufactured by Shimadzu Corporation was used to measure the glass transition temperature and the coefficient of linear expansion (α1, α2) of the sample while increasing the temperature from 30 ° C at a heating rate of 3 ° C / min. A linear expansion coefficient of 40 ° C to 70 ° C is set to α1, and a linear expansion coefficient of 185 ° C to 220 ° C is set to α2. In addition, the thermal expansion coefficient of a sample of 40 ° C to 180 ° C was determined.

From the results shown in Table 1, it is clear that the epoxy resin hardened product obtained using the phenol novolac resin obtained in each Example and the epoxy resin obtained using the phenol novolac resin obtained in each Comparative Example were determined. Compared with hardened materials, the thermal expansion rate is higher when heated, in other words, the thermal shrinkage rate is higher when cooled, and the storage elastic modulus is higher.

In particular, the comparison between Example 1 and Examples 6 to 8 makes it clear that by setting the ratio of the compound of n = 0 in the general formula (1) to a small amount of 5% or less with respect to the entire phenol novolac resin, It can increase the thermal expansion rate of the hardened material and shorten the gelation time.

Further, it is clear from the comparison between Example 1 and Examples 6 to 8 that the ratio of the total of the compound of n = 0 and the compound of n = 1 in the general formula (1) is set to the phenol novolac resin. The total is 10% or less, which can increase the thermal expansion rate of the cured product and shorten the gelation time.

Furthermore, it is clear from the comparison of Examples 6 to 8 that the total ratio of the compound of n = 0 and the compound of n = 1 in the general formula (1) is set to 10% with respect to the entire phenol novolac resin. Below, and the ratio of the compound of n = 2 is set to 5.0% or more and 13.5% or less, the thermal expansion rate of the hardened material can be improved, the gelation time can be shortened, and the storage elastic modulus (elasticity under heat) can be improved. Modulus).

Further, the comparison between Examples 1, 2, 4 and 7 (the substituent R is allyl) and Comparative Examples 1, 2 and 3 (the substituent R is other than the allyl group) can be clarified. When it is set to allyl group, the thermal expansion coefficient of the hardened material can be increased, and the elastic modulus at the time of heat can also be increased. The same situation is also clear from the comparison between Example 1 (substituent R is allyl) and Example 5 (substituent R is third butyl).

In addition, from Example 1 (melting viscosity at 150 ° C: 4.3P, softening point: 73 ° C, storage modulus of elasticity: 86 MPa) and Example 2 (melting viscosity at 150 ° C: 20.0P, softening point: 98 ° C, storage modulus of elasticity) : 33MPa) The comparison shows that if the melt viscosity at 150 ° C is used, the value is more preferably 0.1P or more and less than 20.0P, more preferably 0.1P or more and 10.0P or less, further preferably 0.1P or more and 7.0P. Phenol below 0.1, preferably above 5.0P The production of a hardened body with a novolac resin can increase the thermal modulus of the hardened body. The same situation is also based on Example 7 (150 ° C melt viscosity: 4.3P, softening point: 74 ° C, storage modulus of elasticity: 96MPa) and Example 8 (150 ° C melt viscosity: 29.0P, softening point: 91 ° C, storage The elastic modulus is 26 MPa).

Furthermore, from Example 4 (substituent R: allyl, p = 2, q = 2, softening point: liquid, 150 ° C melt viscosity: <0.1, storage elastic modulus 100 MPa) and Example 3 (substituent group R: allyl, p = 1, q = 1, softening point: liquid, 150 ° C melt viscosity: <0.1, storage modulus of elasticity: 19 MPa) The comparison can be made clearly at q (ene bonded to a phenolic core) In the case where the number of propyl groups) exceeds 1, the case where the melt viscosity of the phenol novolac resin at 150 ° C is low, for example, when the melting viscosity is less than 0.1P, high heat can be obtained. Hardened body with elastic modulus.

[Industrial availability]

As described above, by using the phenol resin of the present invention, a cured product of an epoxy resin composition having a high thermal expansion rate during heating, a high shrinkage rate during cooling, and an elastic modulus during high heat can be obtained by using the phenol resin of the present invention. Therefore, according to the present invention, a phenol resin can be provided, which can be preferably used for an epoxy resin composition of a thin single-sided sealed package.

Claims (11)

A phenol resin represented by the following general formula (1), (In the formula, R represents an allyl group; q represents 1; p represents 1 or 2, which may be the same or different; n represents an integer of 0 or more) The softening point of the phenol resin is 60 ° C or higher and 90 ° C or lower, and It is based on the phenol resin and the following general formula (2) The indicated epoxy resin and the hardened material obtained by the hardening accelerator have a thermal expansion coefficient of 1.5% or higher at 40 ° C or higher and 180 ° C or lower. For example, the phenol resin of claim 1 is one which imparts a storage elastic modulus of 15 MPa or more at 250 ° C to the hardened material. For example, the phenol resin according to claim 1 or 2, wherein the content of the compound of n = 0 in the general formula (1) in the molecular weight distribution measured by a gel permeation chromatography is 5.5 area% or less. The phenol resin according to claim 1 or 2, wherein the dispersion [weight average molecular weight / number average molecular weight] obtained by measurement by a gel permeation chromatography is 1.0 or more and 4.0 or less. An epoxy resin composition comprising the phenol resin and the epoxy resin according to any one of claims 1 to 4. The epoxy resin composition according to claim 5, further comprising a hardening accelerator. The epoxy resin composition as claimed in claim 5 or 6, further comprising an inorganic filler. An epoxy resin hardened product obtained by curing the epoxy resin composition according to any one of claims 5 to 7. For example, the hardened epoxy resin according to claim 8, wherein the thermal expansion coefficient is above 1.5% at 40 ° C to 180 ° C. A semiconductor device having an epoxy resin hardened body as claimed in claim 8 or 9. The semiconductor device as claimed in claim 10, comprising a thin single-sided sealed package.