TW201518394A - Epoxy resin composition, sealing material, cured product thereof, and phenol resin - Google Patents

Abstract

An epoxy resin composition characterized by containing at least an epoxy resin and a phenol resin indicated by a specified chemical formula (1). This epoxy resin composition ideally also contains an inorganic filler material. Also, the mixing ratio for the inorganic filler material in the epoxy resin composition (mass of inorganic filler material/mass of epoxy resin composition including inorganic filler material) is ideally 70-95 % by mass. In addition, ideally, the epoxy resin composition contains a solvent and the epoxy resin and the phenol resin are uniformly dissolved in the solvent.

Description

Epoxy resin composition, encapsulating material, cured product thereof and phenol resin

The present invention relates to an epoxy resin composition, a cured product thereof, a semiconductor encapsulating material using the same, and a phenol resin which can be preferably used in the above epoxy resin composition.

As the encapsulating material of the semiconductor device using the integrated circuit, an epoxy resin, a phenol resin, and an epoxy resin composition prepared by mixing an inorganic filler such as molten cerium oxide or crystalline cerium oxide can be preferably used. The inorganic filler material has the following effects: improving mechanical strength or heat resistance, reducing the thermal expansion rate of the encapsulating material, reducing the amount of warpage, and further reducing the proportion of the resin component which adversely affects water absorption or flame retardancy, thereby achieving low water absorption. Rate or high flame retardancy. However, when the inorganic filler is blended at a high ratio, the melt viscosity of the epoxy resin composition is increased and the fluidity is lowered, which causes difficulty in formability, and may also cause deformation of the lead frame or the wire, peeling of the interface, There are voids, etc., so there are limits.

In recent years, with the increase in the performance, size, and thickness of electronic devices such as smart phones and tablet terminals, the semiconductor devices are accelerating, miniaturization, and thinning. Therefore, in the mounting method of the semiconductor device, a surface mounting method such as a BGA (Ball Grid Array) in which a semiconductor element is directly mounted on a circuit board has become mainstream. Moreover, lead-free soldering is also advancing.

In the reflow step in the manufacture of a semiconductor device, since the lead-free solder is used, the reflow temperature is raised from room temperature to about 260 ° C which is about 20 ° C higher than the previous temperature, and further cooled, thereby causing warpage, but on the surface. In the mounting method, the package is made on one side of the substrate. The material is shaped, so the amount of warpage changes further. Further, if the amount of change in the warpage is large, it is difficult to perform the operation in the subsequent step, and it is easy to cause a quality defect such as solder ball falling off. Further, in the reflow step, the moisture absorbed in the encapsulating material expands to easily cause cracks.

In the method of improving the moldability, the reflow resistance, and the like, it is proposed to use an inorganic filler having an average particle diameter of 13 μm or less. Further, in Patent Documents 2 and 3, as a method for suppressing warpage of the package and improving the reflow resistance, it is proposed to use a glycidyl ether type epoxy resin having an anthracene ring or a naphthalene ring, or a naphthalene ring. Phenol resin. However, there is still room for improvement regarding formability, suppression of warpage, improvement in reflow resistance, and the like.

Patent Document 4 discloses that the molecular weight distribution of a phenol resin using a specific raw material is controlled, whereby the reduction in heat resistance or softening point is suppressed and the low viscosity is achieved. However, the fluidity, the formability, and the improvement of each characteristic in the case of an epoxy resin composition containing an inorganic filler which is particularly useful as a sealing material have not been studied in detail.

[Previous Technical Literature] [Patent Literature]

Patent Document 1: Japanese Patent Laid-Open Publication No. 2008-274041

Patent Document 2: US2007/207322A1

Patent Document 3: Japanese Patent Laid-Open Publication No. 2013-10903

Patent Document 4: Japanese Patent Laid-Open Publication No. SHO 63-275620

According to the state of such a semiconductor device, there is a demand for an epoxy resin composition which can be formulated with a high proportion of an inorganic filler, which is excellent in fluidity and formability, and has heat resistance, low water absorption, and low modulus of elasticity (especially It has high temperature and low modulus of elasticity, and flame retardancy, and is preferably used as a semiconductor packaging material in a surface mount semiconductor device.

Furthermore, it can be considered that the reason for the demand for low elastic modulus (especially high temperature and low elastic modulus) is In order to better alleviate the stress generated in the thermal cycle in each step including the reflow step, reduce the amount of warpage, and suppress the occurrence of cracks, the low elastic modulus (especially the high temperature and low elastic modulus) is effective. .

That is, the present invention proposes an epoxy resin composition, a cured product thereof, a semiconductor encapsulating material using the same, and a phenol resin which can be preferably used in the epoxy resin composition, and the above epoxy resin composition can be made higher The ratio of the inorganic filler to the semiconductor device is excellent in fluidity and formability, and has heat resistance, low water absorption, low modulus of elasticity (especially high temperature and low modulus of elasticity), and flame retardancy, and is a surface mount type semiconductor device. It can be preferably used as a semiconductor encapsulating material.

That is, the present invention relates to the following matters.

An epoxy resin composition comprising at least an epoxy resin and a phenol resin represented by the following chemical formula (1),

In the chemical formula (1), R1 and R2 are each independently a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, an allyl group, or an aryl group, and R3 and R4 are each independently a hydrogen atom, a hydroxyl group, or a carbon. Any one of an alkyl group, an allyl group, or an aryl group having a number of 1 to 6, wherein n is 0 or a positive integer, and n = 1 relative to the area ratio of all of the above phenol resins by gel permeation chromatography analysis. The composition is 30% or more, and the component of n=0 is 25% or less.

Further, n is preferably substantially (90% or more of the total components) is an integer of 0 to 8, and further, the component of n = 1 is preferably a principal component which accounts for the largest proportion of the total components.

Further, R2 may be a hydrogen atom, or each of R1 may be an alkyl group, an allyl group or an aryl group having 1 to 6 carbon atoms, and each of R3 is a hydrogen atom and has a carbon number of 1 to 6. Any one of an alkyl group, an allyl group, or an aryl group, and each of R2 and each of R4 is a hydrogen atom.

Further, R1 may be an alkyl group having 1 to 6 carbon atoms and being in the ortho position of the hydroxyl group, and R2 is a hydrogen atom, or may be an alkyl group having a carbon number of 1 to 6 and a position adjacent to the hydroxyl group. R2 is a state other than the state of a hydrogen atom.

Further, the component of n=1 may preferably be 55% or less, more preferably 50% or less, still more preferably 47% or less, and still more preferably 45% or less. When the component of n = 1 exceeds the above preferred range, the glass transition temperature of the obtained cured product is lowered to obtain sufficient heat resistance.

2. The epoxy resin composition according to item 1, wherein in the chemical formula (1), the component of n=1 is 30% or more and 50% or less, and more preferably, the component of n=1 is 30% or more and 47%. Hereinafter, it is more preferable that the component of n=1 is 30% or more and 45% or less.

3. The epoxy resin composition according to item 1, wherein, in the chemical formula (1), R1 is an alkyl group having 1 to 6 carbon atoms and is ortho to the hydroxyl group, and R2 is a hydrogen atom, and the component of n=1 is 35% or more and 50% or less, the component of n=0 is 25% or less, and is a ratio of 1/3 times or more with respect to the component of n=1.

4. The epoxy resin composition according to any one of items 1 to 3 above, which further comprises an inorganic filler.

5. The epoxy resin composition according to item 4 above, wherein the proportion of the inorganic filler in the epoxy resin composition [the mass of the inorganic filler/the mass of the epoxy resin composition comprising the inorganic filler] is 70~ 95% by mass.

6. The epoxy resin composition according to any one of items 1 to 5 above, which further contains a solvent, and the epoxy resin and the phenol resin are uniformly dissolved in the solvent.

A cured product obtained by hardening the epoxy resin composition according to any one of items 1 to 6 above.

A semiconductor encapsulating material comprising the epoxy resin composition according to any one of items 1 to 6 above.

9. The semiconductor package material according to item 8 above, which is used for a surface mount type semiconductor device.

A semiconductor device using the semiconductor package material according to any one of items 8 or 9 above.

A phenol resin represented by the following chemical formula (2),

In the chemical formula (2), R1 and R2 are each independently a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, an allyl group, or an aryl group, and R3 and R4 are each independently a hydrogen atom, a hydroxyl group, or a carbon. Any one of alkyl, allyl, or aryl groups of 1 to 6, n is 0 or a positive integer, and relative to all phenol resins, the area ratio by gel permeation chromatography is analyzed, n=1 The composition is 30% or more and 50% or less.

According to the present invention, the following epoxy resin composition, a cured product thereof, a semiconductor encapsulating material using the same, and a phenol resin which can be preferably used in the epoxy resin composition can be obtained. High proportion of inorganic filler materials, excellent fluidity and formability, heat resistance, low water absorption, low modulus of elasticity (especially high temperature and low modulus of elasticity), and flame retardancy, and surface mount semiconductors It can be preferably used as a semiconductor packaging material in the device.

Fig. 1 is a chart showing gel permeation chromatography analysis of a phenol novolak resin obtained in Example 1.

2 is a chart of gel permeation chromatography analysis of a phenol novolak resin obtained in Example 2.

Fig. 3 is a chart showing the gel permeation chromatography analysis of the phenol novolak resin obtained in Example 3.

Figure 4 is a graph showing the gel permeation chromatography analysis of the phenol novolak resin obtained in Example 4.

Figure 5 is a graph showing the gel permeation chromatography analysis of the phenol novolak resin obtained in Example 5.

Figure 6 is a graph showing the gel permeation chromatography analysis of the phenol novolak resin obtained in Example 6.

Fig. 7 is a chart showing gel permeation chromatography analysis of a phenol novolak resin obtained in Comparative Example 1.

Fig. 8 is a chart showing gel permeation chromatography analysis of a phenol novolak resin obtained in Comparative Example 2.

The present invention relates to an epoxy resin composition comprising at least an epoxy resin and a phenol resin represented by the above chemical formula (1).

The epoxy resin used in the epoxy resin composition of the present invention is not particularly limited, and an epoxy resin generally used in the epoxy resin composition can be preferably used. For example, bisphenol A type epoxy resin, bisphenol F type epoxy resin, cresol novolak type epoxy resin, phenol novolak type epoxy resin, naphthol novolac type epoxy resin, phenol can be preferably enumerated. Aralkyl type epoxy resin, especially phenol biphenylmethylene type epoxy resin, trisphenol methane type epoxy resin, stilbene type epoxy resin, dicyclopentadiene type epoxy resin, biphenyl type a difunctional or polyfunctional group having two or more epoxy groups in a molecule such as a glycidyl ether type epoxy resin such as an epoxy resin, a glycidyl ester type epoxy resin, a glycidylamine type epoxy resin, or a halogenated epoxy resin. Epoxy resin. The epoxy resin may be used alone or in combination of two or more.

One of the characteristics of the epoxy resin composition of the present invention is that the phenol resin represented by the chemical formula (1) is contained as a curing agent. Further, the phenol resin represented by the chemical formula (1) is particularly characterized in that the composition of n = 1 is 30% or more of all phenol resins by the area ratio of gel permeation chromatography, and the component of n = 0 is all A ratio of 25% or less of the phenol resin.

The epoxy resin composition of the present invention exerts an advantageous effect by using a phenol resin satisfying the above conditions: the fluidity or melt viscosity of the epoxy resin composition can be preferably lowered. Further, since the epoxy resin composition is improved in kneading property when the inorganic filler is kneaded, the inorganic filler can be easily blended at a high ratio, and the moldability is excellent. Further, the cured product obtained by curing the epoxy resin composition is preferably improved in heat resistance, low water absorbability, low modulus of elasticity (especially high temperature and low modulus of elasticity), and flame retardancy.

The phenol resin used in the epoxy resin composition of the present invention is preferably an area ratio by gel permeation chromatography, and the component of n = 1 is 30% or more and 50% or less of all the phenol resins. The epoxy resin composition of the present invention can easily obtain a better softening point or melt viscosity by using a phenol resin satisfying such conditions. The measurement conditions of the gel permeation chromatography analysis and the method of calculating the area of each component will be described in detail in the following examples.

The phenol resin represented by the chemical formula (1) used in the epoxy resin composition of the present invention can be preferably produced by a production method comprising the following steps: a first step which is represented by the following chemical formula (3) The phenolic resin is reacted with formaldehyde or a formaldehyde generating substance in the presence of a basic catalyst; and the second step, the reaction obtained in the first step The phenol represented by the following chemical formula (4) is added to the mixture, and the novolak reaction is carried out in the presence of an acid catalyst.

The ratio of each component of the phenol resin of the present invention can be easily achieved by adjusting the ratio of the reaction raw materials, the reaction time, and the reaction temperature as described below. Further, the actual reaction conditions can be determined with high precision by a person skilled in the art by performing a preliminary test as needed.

In the chemical formula (3), R1 and R2 are each a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, an allyl group, or an aryl group.

In the chemical formula (4), R3 and R4 are each a hydrogen atom, a hydroxyl group, an alkyl group having 1 to 6 carbon atoms, an allyl group, or an aryl group.

The first step will be described.

The ratio of the phenol to the formaldehyde or the formaldehyde-producing substance represented by the chemical formula (3) which is reacted in the first step, the formaldehyde or the formaldehyde generated from the formaldehyde-generating substance expressed by the chemical formula (3) It is preferably 1 to 3 moles, more preferably 1.5 to 2.5 moles. When the ratio is less than the lower limit of the preferred range, the low molecular weight component is increased. When the ratio is more than the upper limit of the preferred range, the high molecular weight component is increased. Therefore, it is difficult to obtain the phenol resin represented by the chemical formula (1) of the present invention.

The amount of the basic catalyst to be used is not limited, and is preferably 0.1 to 1.5 moles, more preferably 0.3 to 1.0 moles, based on the phenolic 1 mole represented by the chemical formula (3). When the ratio is less than the lower limit of the preferred range, the progress of the reaction becomes slow, and the unreacted component tends to remain. When the ratio exceeds the upper limit of the preferred range, it is difficult to remove the catalyst and the productivity is lowered.

The reaction temperature is not limited, but is preferably about 10 to 80 ° C, more preferably 20 to 60 ° C. If it is less than 10 ° C, the progress of the reaction becomes slow. When it exceeds 80 ° C, the polymerization is easy, and it is difficult to control the resol phenolization reaction. The reaction time is not limited, but is preferably 0.5 to 24 hours, more preferably 3 to 12 hours.

The phenol represented by the above chemical formula (3) used in the first step is not particularly limited, and examples thereof include phenol, cresol, ethylphenol, propylphenol, butylphenol, and allyl group. Phenol, phenylphenol, xylenol, diethylphenol, dipropylphenol, dibutylphenol, catechol, resorcinol, and the like. Among these, o-cresol or p-cresol is preferred from the viewpoint of economy or low melt viscosity. The phenols may be used alone or in combination of two or more.

As the formaldehyde used in the first step, it is preferred to use an aqueous solution of formaldehyde. Further, as the formaldehyde generating substance, paraformaldehyde or trisole is preferably used. Alkane, four A compound such as an alkane which produces formaldehyde.

The alkaline catalyst used in the first step may, for example, be an alkali metal hydroxide such as sodium hydroxide or lithium hydroxide or a hydroxide of an alkaline earth metal such as calcium hydroxide or barium hydroxide. Amines such as ammonium hydroxide, diethylamine, triethylamine, triethanolamine, ethylenediamine, and hexamethylenetetramine. The basic catalyst may be used singly or in combination of two or more kinds.

Next, the second step will be described.

The reaction in the second step is preferably carried out by adding the phenol represented by the chemical formula (4) to the reaction mixture obtained in the resol phenolization reaction of the first step, neutralizing with an acidic compound, and further adding an acid catalyst. It is preferably carried out later.

As the acidic compound to be neutralized, hydrochloric acid, sulfuric acid, phosphoric acid, formic acid, acetic acid, oxalic acid, butyric acid, lactic acid, benzenesulfonic acid, p-toluenesulfonic acid or the like can be preferably used. The acidic compound may be used alone or in combination of two or more.

The phenol represented by the chemical formula (4) used in the second step is preferably 0.5 to 5 moles, more preferably 0.5 to 5 moles, based on the formaldehyde used in the first step or the formaldehyde 1 molar produced by the formaldehyde generating substance. Good for 1~2 moles. When the amount of the phenols represented by the chemical formula (4) is less than the lower limit of the preferred range, the high molecular weight component is increased, and the melt viscosity of the obtained phenol resin is increased, and if it exceeds the upper limit of the preferred range, the unreacted phenol is obtained. The class is easily left in large quantities.

The amount of the acid catalyst used in the second step is preferably 0.0001 to 0.07 mol, more preferably phenolic 1 mol expressed by the chemical formula (3) used in the first step. It is a ratio of 0.0005 to 0.05 mol. If the ratio is less than the lower limit of the preferred range, the progress of the reaction becomes slow, and if it exceeds the upper limit of the preferred range, the polymer concentration is easily performed, so that it is difficult to control the reaction.

The reaction temperature is not limited, but is preferably about 50 to 150 ° C, more preferably about 70 to 100 ° C. If the temperature is less than 50 ° C, the progress of the reaction becomes slow. When the temperature exceeds 150 ° C, the polymer is easily polymerized by heat generation, and it is difficult to control the novolak reaction.

The reaction time is not limited, but is preferably from 0.5 to 12 hours, more preferably from 1 to 6 hours. If the ratio is less than the lower limit of the preferred range, the progress of the reaction becomes insufficient, and if it exceeds the upper limit of the preferred range, the molecular weight is easily obtained.

There is no particular limitation on the phenols represented by the chemical formula (4) used in the second step. Preferably, phenol, cresol, ethyl phenol, propyl phenol, butyl phenol, allyl phenol, phenyl phenol, xylenol, diethyl phenol, dipropyl phenol, dibutyl Phenolic, catechol, resorcinol and the like. Among these, o-cresol or p-cresol is preferred from the viewpoint of economy or low melt viscosity. The phenols may be used alone or in combination of two or more.

The acid catalyst used in the second step is preferably hydrochloric acid, sulfuric acid, phosphoric acid, formic acid, acetic acid, oxalic acid, butyric acid, lactic acid, benzenesulfonic acid or p-toluenesulfonic acid. The acid catalyst may be used singly or in combination of two or more kinds.

The phenol resin used in the present invention can be preferably obtained by subjecting the novolak-reacted reaction mixture obtained in the second step to a subsequent treatment such as washing with water or concentration under reduced pressure to remove unreacted phenol. Class or catalyst.

The weight average molecular weight of the phenol resin used in the present invention obtained in the above manner is not particularly limited, but is preferably 500 to 1,000, more preferably 550 to 800, still more preferably 600 to 750. Further, the degree of dispersion [weight average molecular weight / number average molecular weight] is preferably from 1.0 to 1.2.

The epoxy resin composition of the present invention can be preferably obtained, for example, by using a mixing device such as a biaxial kneader or a two-roll kneader to treat at least an epoxy resin and a phenol resin represented by the chemical formula (1). It needs to be melted and mixed. The obtained epoxy resin composition is preferably powdered by a pulverizer.

The epoxy resin composition of the present invention may preferably contain an organic or inorganic filler. The filler is not particularly limited and is selected depending on the application, and examples thereof include amorphous cerium oxide, crystalline cerium oxide, aluminum oxide, calcium silicate, calcium carbonate, talc, mica, and barium sulfate. Inorganic filler materials such as magnesium oxide. Particularly in the case of being used as a semiconductor encapsulating material, amorphous ceria or crystalline ceria or the like can be preferably used.

Proportion of the epoxy resin composition in the case of blending an inorganic filler material [None The mass of the machine filler/the mass of the epoxy resin composition containing the inorganic filler is not limited, and is preferably from 30 to 98% by mass, preferably from 40 to 95% by mass. In the case of use as a sealing material for a semiconductor element, it is 60 to 95% by mass, preferably 70 to 95% by mass, more preferably 75 to 90% by mass, still more preferably 80 to 90% by mass.

If the ratio of the inorganic filler is less than the lower limit of the above range, the water absorption rate of the cured product of the epoxy resin composition increases, which is not preferable. Further, when the ratio of the inorganic filler is too large as compared with the upper limit of the above range, the fluidity of the epoxy resin composition for semiconductor encapsulation is impaired.

The epoxy resin composition of the present invention may further contain an additive such as a curing accelerator, a releasing agent, a coloring agent, a coupling agent, and a flame retardant used in a usual epoxy resin composition, and further a solvent.

The solvent is preferably a resin component such as an epoxy resin or a phenol resin, and an organic solvent such as an alcohol, an ether, a ketone, a lactone or a compound containing a hetero atom can be preferably used. The epoxy resin composition of the present invention obtained by uniformly dissolving a resin component such as an epoxy resin or a phenol resin in a solvent is impregnated into glass fibers, carbon fibers, or the like, and then B-staged while removing the solvent. Alternatively, a fiber reinforced composite material or a laminate can be preferably obtained.

The curing accelerator used in the epoxy resin composition may be one which promotes the curing reaction between the epoxy resin and the phenol resin, and examples thereof include an organic phosphine compound, a boron salt thereof, a tertiary amine, and a quaternary ammonium salt. Salts, imidazoles, and tetraphenylboron salts thereof.

The amount of the additive such as the curing accelerator, the releasing agent, the coloring agent, the coupling agent, and the flame retardant, and the amount of the solvent to be used are not particularly limited, and may be the same as those in the known epoxy resin composition.

The epoxy resin composition of the present invention can be preferably used as an encapsulating material for a semiconductor element. Depending on the package form, the package material of the semiconductor device includes a package material for encapsulating the gap between the semiconductor device and the circuit substrate and surrounding the semiconductor device, and the semiconductor device A primer filling material encapsulated in a gap with the circuit substrate. Further, in recent years, for the purpose of cost reduction, there is also a molding primer filling material used in a molding method in which a primer is simultaneously filled by transfer molding. The epoxy resin composition of the present invention can be preferably used in these package forms. That is, the encapsulating material of the present invention comprises a primer filling material and a forming primer filling material.

The epoxy resin composition of the present invention can be subjected to a curing reaction by, for example, heating at 100 to 350 ° C for 0.01 to 20 hours to obtain a cured product. If the temperature of the hardening reaction is low, it will not harden, and if it is high, the performance degradation due to pyrolysis will occur. Further, if the hardening reaction time is short, the reaction is not completed, and if it is long, the productivity is lowered.

A semiconductor device having a semiconductor device encapsulated by a package material comprising the epoxy resin composition of the present invention can be preferably obtained by introducing a method comprising the present invention between a gap between the semiconductor device and the circuit substrate and around the semiconductor device a method of forming and hardening an encapsulating material of an epoxy resin composition, that is, a step of introducing a primer filling material into a gap between a semiconductor element and a circuit substrate, and a step of forming a hardening step of the underfill material, or The method includes a step of introducing a sealing material between a gap between the semiconductor element and the circuit board and around the semiconductor element, and a method of forming and hardening the sealing material.

The epoxy resin composition of the present invention can be formulated with an inorganic filler in a high ratio, and has excellent fluidity and formability, and the cured product has excellent heat resistance, low water absorption, and low modulus of elasticity (especially high temperature and low elasticity). Modulus) and flame retardancy. Therefore, the epoxy resin composition of the present invention can be preferably used as a semiconductor encapsulating material in a surface mount type semiconductor device.

[Examples]

Hereinafter, the present invention will be specifically described by way of Examples, but the present invention is not limited to the Examples.

The measurement methods used in the following examples will be described.

(1) Determination method related to phenol resin [Measurement of molecular weight distribution]

The phenol resin was analyzed by gel permeation chromatography analysis in the following manner. Further, the ratio (area ratio) of each component was calculated using the analysis software Multi Station GPC-8020. At this time, the straight line portion before and after the peak is used as the baseline (0 value), and the peak is distinguished by the slitting where the peaks of the respective components become the lowest. The sampling interval is set to 500 milliseconds. Further, the molecular weight (Mw, Mn) or the degree of dispersion (Mw/Mn) was calculated from standard polystyrene conversion.

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

Column: TSK-GEL H type

G2000H×L 4 roots

G3000H×L 1 root

G4000H×L 1 root

Measurement conditions: column pressure 13.5MPa

Solution: tetrahydrofuran (THF, Tetrahydrofuran)

Flow rate: 1mL/min

Measuring temperature: 40 ° C

Detector: Spectroscopic Spectrometer (UV-8020)

RANGE (range): 2.56 WAVE LENGTH (wavelength) 254 nm

(2) Determination method relating to epoxy resin composition containing no inorganic filler [Measurement of viscosity]

The ICI viscosity at 150 ° C was measured in the following manner.

Device: ICI cone and plate viscometer (TOA Industry Co., Ltd., MODEL CV-1S)

Measuring temperature: 150 ° C

Determination method: after setting the plate temperature to 150 ° C, placing a specific amount on the plate The sample was brought into contact with the cone from above and rotated after the sample was melted. After the temperature was stabilized, the moment value was read to calculate the ICI viscosity.

[Measurement of softening point]

The softening point was measured in the following manner.

Device: Dropping point, softening point measuring system (Mettler-Toledo Co., Ltd., FP83HT)

Heating rate: 2 ° C / min

Determination method: a molten sample is placed in the sample cup to be cooled and solidified. After being placed in a crucible having a slit for light transmission, it is set on a heating furnace and heated at a specific temperature increase rate. The sample is melted by heating, and the temperature of the light that blocks the transmission through the slit is detected by the photocell.

(3) A method for determining the kneading property of an inorganic filler when preparing an epoxy resin composition [mixedness]

The kneadability of the inorganic filler was measured in the following manner.

A specific amount of the epoxy resin, the phenol resin, and the inorganic filler cerium oxide were kneaded at a temperature of 63 ° C using a two-roll kneader, and the recovered kneaded material was visually evaluated. The basis of the evaluation was set to ○: a uniform sheet-like kneaded material could be obtained without problems; Δ: a sheet-like kneaded material could be obtained, but the side surface was rough (uneven); ×: the kneading could not be obtained or the sheet could not be obtained. Mixtures.

(4) Determination method relating to epoxy resin composition containing inorganic filler

The epoxy resin composition containing an inorganic filler was measured as follows. Further, in the measurement, a powder of a mixture of an epoxy resin composition containing an inorganic filler is formed into a sheet, and the sheet or a cured product using the same is used as a sample. The sheet was formed by pressurization with a hand pressure of 450 MPa for 1 minute.

[liquidity (spiral flow)]

The sheet of the sample was measured for fluidity at the time of molding in the following manner.

Device: Transfer Forming Machine (Tokura Manufacturing Co., Ltd., 60 t)

Measurement conditions: mold temperature 170 ° C, injection pressure 6.9 MPa, hold time 120 seconds

Measurement method: The sample was injected into a mold for measuring a spiral flow according to EMMI-1-66, and the flow length was measured.

[Mechanical strength]

The measurement was carried out in accordance with JIS K7171.

The sheet was formed into a shape of a length of 80 mm × a width of 10 mm × a thickness of 4 mm by a transfer molding machine, followed by heating at 180 ° C for 8 hours to obtain a test piece (cured product). The bending modulus and the bending strength of the test piece were measured by a 3-point bending test at room temperature.

[High temperature storage modulus]

The sheet was formed into a shape having a length of 127 mm × a width of 13 mm × a thickness of 1 mm by a transfer molding machine, followed by heating at 180 ° C for 8 hours to obtain a cured product. The cured product was cut into a shape having a length of 35 mm, a width of 13 mm, and a thickness of 1 mm to obtain a test piece. A DMA (Dynamic Mechanical Analysis) measuring apparatus (RSA-G2 manufactured by TA Instruments Co., Ltd.) was used for the test piece, and the temperature was raised from 30 ° C at a temperature increase rate of 3 ° C/min, and the storage modulus at 270 ° C was measured.

[Water absorption (water absorption)]

The sheet was formed into a shape having a diameter of 50 mm × a thickness of 3 mm by a transfer molding machine, followed by heating at 180 ° C for 8 hours to obtain a test piece (cured product).

The test piece was measured for the amount of water absorption after immersion in water at 95 ° C for 24 hours. Further, the water absorption rate was calculated by the following formula.

Water absorption rate (%) = [(mass after water absorption - mass before water absorption) / (mass before water absorption)] × 100

[flammability resistance (flame retardancy)]

The sheet was formed into a length of 127 mm × width 13 mm × thickness 1 mm by a transfer molding machine The shape was then heated at 180 ° C for 8 hours to obtain a test piece (hardened product). Using this test piece, the flame retardancy was measured in accordance with UL-94.

[glass transition temperature]

The sheet was formed into a shape having a length of 127 mm × a width of 13 mm × a thickness of 1 mm by a transfer molding machine, followed by heating at 180 ° C for 8 hours to obtain a cured product. The cured product was cut into a shape having a length of 35 mm, a width of 13 mm, and a thickness of 1 mm to obtain a test piece. A DMA measuring apparatus (RSA-G2 manufactured by TA Instruments Co., Ltd.) was used for the test piece, and the temperature was raised from 30 ° C to 270 ° C at a temperature increase rate of 3 ° C/min, and the glass transition temperature was measured.

Next, materials such as an epoxy resin used in the following examples will be described.

(a) Epoxy resin

EPPN-501H: Made by Nippon Kayaku Co., Ltd., epoxy resin of trisphenol methane type, epoxy equivalent 166g/eq

(2) Hardening accelerator

Triphenylphosphine: manufactured by Beixing Chemical Co., Ltd.

(3) Inorganic filler

Ceria: manufactured by Ronson Co., Ltd., Kikurosu MSR-2212, average particle size 25μm

The preparation examples of the phenol resin will be described below.

[Example 1] Synthesis of phenol resin A

In a four-necked flask equipped with a thermometer, a condenser, and a stirring device, 54.00 g (0.500 mol) of 2-methylphenol, 71.43 g (1.000 mol) of 42% fumarin, and 25% of alkaline catalyst were charged. Solvent phenol resination reaction of the first step was carried out by reacting 60.00 g (0.375 mol) of sodium hydroxide at 30 ° C for 5 hours. 120.00 g (1.111 mol) of 2-methylphenol was added to the reaction mixture, and after neutralizing by adding 25% of hydrogen chloride, 2.16 g (0.017 mol) of oxalic acid as an acid catalyst was further added, and the reaction was carried out at 70 ° C. In the hour, the reaction was carried out at 100 ° C for 1 hour to carry out the novolak reaction of the second step.

The temperature of the obtained reaction mixture was lowered to 95 ° C, and water washing was performed twice with 370 g of pure water of the same temperature. After washing with water, the temperature was raised to 165 ° C, and unreacted components were removed by steam distillation under a reduced pressure of -760 mmHg, whereby phenol resin A was obtained.

[Example 2] Synthesis of Phenol Resin B

The phenol resin B was obtained by the same operation as in Example 1 except that the amount of the 2-methylphenol in the second step was changed to 154.28 g (1.429 mol).

The graph of the obtained phenol resin B as measured by gel permeation chromatography is shown in Fig. 1.

[Example 3] Synthesis of Phenol Resin C

The phenol resin C was obtained by the same operation as in Example 1 except that the amount of the 2-methylphenol in the second step was changed to 216.00 g (2.000 mol).

[Example 4] Synthesis of phenol resin D

The phenol resin D was obtained by the same operation as in Example 1 except that the amount of the 2-methylphenol in the first step was changed to 43.20 g (0.400 mol).

[Example 5] Synthesis of phenol resin E

Phenol resin E was obtained by the same operation as in Example 2 except that 4-methylphenol was used instead of 2-methylphenol in the first step.

[Example 6] Synthesis of Phenol Resin F

Phenol resin F was obtained by the same operation as in Example 2 except that 2-phenylphenol was used instead of 2-methylphenol in the first step.

[Comparative Example 1] Synthesis of phenol resin G

In a four-necked flask equipped with a thermometer, a condenser, and a stirring device, 54.00 g (0.500 mol) of 2-methylphenol, 71.43 g (1.000 mol) of 42% fumarin, and 25% of alkaline catalyst were charged. 19.40 g (0.121 mol) of sodium hydroxide was reacted at 60 ° C for 5 hours to carry out the resol phenolization reaction of the first step. Into the reaction mixture, 156.06 g (1.408 mol) of 2-methylphenol was added, and after neutralizing by adding 25% of hydrogen chloride, it was further put into acid. 2.71 g (0.017 mol) of oxalic acid of the catalyst was reacted at 70 ° C for 3 hours to carry out the novolak reaction of the second step.

After the obtained reaction mixture was washed with water, the unreacted components were removed by steam distillation under reduced pressure, whereby phenol resin F was obtained.

[Comparative Example 2] Synthesis of phenol resin H

Phenol resin G was obtained by the same operation as in Example 2 except that phenol 134.28 g (1.429 mol) was used instead of 2-methylphenol in the second step.

The molecular weight distribution of each of the phenol resins A to G obtained in Examples 1 to 5 and Comparative Examples 1 and 2 was measured, and the ratio (area ratio) and the Mw/Mn value of each component were determined.

Further, an epoxy resin (EPPN-501H) and a phenol resin A to G were weighed into a SUS container in such a manner that the ratio of the epoxy resin equivalent to the hydroxyl equivalent was equal, and the mixture was melted and mixed on a hot plate to prepare no. An epoxy resin composition containing an inorganic filler and measuring its softening point or ICI viscosity at 150 °C.

The results are shown in Table 1.

Moreover, the kneadability of the inorganic filler in the case of preparing the epoxy resin composition using the phenol resin of Example 2 and Comparative Example 1 was evaluated. The evaluation was carried out by dissolving cerium oxide in an amount of 91 parts by mass or 92% by mass in the composition of 100 parts by mass of the epoxy resin and 70 parts by mass of the phenol resin.

The results are shown in Table 2.

Further, using the phenol resin of Example 2 and Comparative Example 1, an epoxy resin composition containing an inorganic filler was prepared and evaluated.

The results are shown in Table 3.

[Industrial availability]

According to the present invention, the following epoxy resin composition, a cured product thereof, a semiconductor encapsulating material using the same, and a phenol resin which can be preferably used in the epoxy resin composition can be obtained. A semiconductor device with a high ratio of fluidity and formability, high heat resistance, low water absorption, low modulus of elasticity (especially high temperature and low modulus of elasticity), and flame retardancy, and surface mount type It can be preferably used as a semiconductor encapsulating material.

Claims (11)

An epoxy resin composition comprising at least an epoxy resin and a phenol resin represented by the following chemical formula (1); In the chemical formula (1), R1 and R2 are each independently a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, an allyl group, or an aryl group, and R3 and R4 are each independently a hydrogen atom, a hydroxyl group, or a carbon. Any one of an alkyl group, an allyl group, or an aryl group having a number of 1 to 6, wherein n is 0 or a positive integer, and n = 1 relative to the area ratio of all of the above phenol resins by gel permeation chromatography analysis. The composition is 30% or more, and the component of n=0 is 25% or less. The epoxy resin composition of claim 1, wherein in the chemical formula (1), the component of n=1 is 30% or more and 50% or less. The epoxy resin composition of claim 1, wherein in the chemical formula (1), R1 is an alkyl group having 1 to 6 carbon atoms and is ortho to the hydroxyl group, R2 is a hydrogen atom, and a component of n=1 is 35%. Above 50% or less, the component of n=0 is 25% or less and the ratio of the component of n=1 is 1/3 or more. The epoxy resin composition of claim 1, which further contains an inorganic filler. The epoxy resin composition of claim 4, wherein the proportion of the inorganic filler in the epoxy resin composition [the mass of the inorganic filler/the mass of the epoxy resin composition comprising the inorganic filler] is 70 to 95 mass %. The epoxy resin composition of claim 1, which further contains a solvent, and an epoxy resin and The phenol resin is uniformly dissolved in the solvent. A cured product obtained by hardening the epoxy resin composition of claim 1. A semiconductor package material comprising the epoxy resin composition of claim 1. The semiconductor package material of claim 8, which is used in a surface mount semiconductor device. A semiconductor device using the semiconductor package material of any one of claims 8 or 9. A phenol resin represented by the following chemical formula (2), In the chemical formula (2), R1 and R2 are each independently a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, an allyl group, or an aryl group, and R3 and R4 are each independently a hydrogen atom, a hydroxyl group, or a carbon. Any one of alkyl, allyl, or aryl groups of 1 to 6, n is 0 or a positive integer, and relative to all phenol resins, the area ratio by gel permeation chromatography is analyzed, n=1 The composition is 30% or more and 50% or less.