JP5005272B2 - Semiconductor sealing resin composition and semiconductor device - Google Patents

Description

  The present invention relates to a resin composition for encapsulating a semiconductor and a semiconductor device using the same, and in particular, a resin composition for encapsulating a semiconductor having excellent laser marking properties and good insulation reliability, and a semiconductor using the same. Relates to the device.

  Conventionally, in a resin-encapsulated semiconductor device, marking is performed using a thermosetting or UV curable special ink. However, in such a method, it takes time for marking and curing thereof, and handling of ink is not easy.

  For this reason, at present, it is the mainstream to perform marking using a YAG laser or a carbonic acid laser. Marking using a YAG laser or a carbonic acid laser has many advantages such as excellent workability and greatly shortening the working time compared to marking with ink.

  However, in the marking using a YAG laser or a carbonic acid laser, the marking is unclear because the contrast between the marked portion and the unmarked portion is not sufficient. In addition, reading may be difficult due to yellowing due to oxidation of the phenol resin curing agent in the sealing resin.

  Therefore, in the sealing resin composition used for sealing of such a semiconductor device, various studies have been conducted in order to improve laser marking properties. For example, carbon black is used as a black pigment, and its average It has been proposed to specify the range of the particle diameter and the amount added (see, for example, Patent Documents 1 to 3).

However, since carbon black has conductivity, there is a risk of causing a conduction failure (short circuit) when applied to sealing of high-definition wiring accompanying the recent increase in the density of semiconductor devices. In order to solve this problem, it has been proposed to use fullerene that has a low risk of conduction failure (short circuit) instead of carbon black (see, for example, Patent Document 4). No one with the characteristics has been obtained.
JP-A-10-158479 JP 2001-123047 A JP 2005-89645 A JP-A-2005-206768

  The present invention has been made in order to solve the above-described problems, and sufficient contrast can be obtained by marking with a laser, and clear marking is possible. In addition, poor conduction occurs even when applied to high-definition wiring. An object of the present invention is to provide a resin composition for sealing a semiconductor device and a semiconductor device using the same.

  (A) epoxy resin, (B) phenol resin curing agent, (C) inorganic filler, (D) fullerene, and (E) insoluble in organic solvents, and in the X-ray diffraction measurement analysis using CuKα rays A resin composition for encapsulating a semiconductor containing a carbon material having a strongest peak within a range of a diffraction angle of 10 to 18 ° within a range of a folding angle of 3 to 30 °, and the entire resin composition for encapsulating a semiconductor The component (C) is 70 to 95% by weight, the component (D) is 0.01 to 2.0% by weight, and the component (E) is 0.01 to 2.0% by weight. It is characterized by.

  The semiconductor device of the present invention comprises a semiconductor element sealed with a cured product of the above-described resin composition for encapsulating a semiconductor of the present invention.

  According to the present invention, a resin composition for encapsulating a semiconductor device in which sufficient contrast is obtained by marking with a laser, clear marking is possible, and conduction failure does not occur even when applied to high-definition wiring. And a semiconductor device using the same are provided.

  Embodiments of the present invention will be described below.

  The resin composition for semiconductor encapsulation of the present invention is insoluble in (A) an epoxy resin, (B) a phenol resin curing agent, (C) an inorganic filler, (D) fullerene, and (E) an organic solvent, and It contains a carbon material having the strongest peak in the diffraction angle range of 10 to 18 ° within the diffraction angle range of 3 to 30 ° in the X-ray diffraction measurement analysis using CuKα rays. And 70-95 weight% of the inorganic filler which is (C) component, 0.01-2.0 weight% of fullerene which is (D) component with respect to the whole resin composition for semiconductor sealing, (E ) A carbon material having specific physical properties as a component is contained in an amount of 0.01 to 2.0% by weight.

  The epoxy resin as the component (A) used in the present invention is not particularly limited as long as it has two or more epoxy groups in one molecule. What is used for sealing can be used widely. Specific examples of the epoxy resin include aliphatic epoxy resins such as phenol novolac type epoxy resins, cresol novolac type epoxy resins and dicyclopentadiene derivatives, and aromatic epoxy types such as biphenyl type, naphthyl type and bisphenol type. Resin etc. are mentioned. These epoxy resins may be used alone or in combination of two or more.

  The phenol resin curing agent (B) used in the present invention is not particularly limited as long as it has two or more phenolic hydroxyl groups in one molecule, and is generally not limited. What is used as a hardening agent of resin can be used widely. Specific examples of the phenol resin curing agent include, for example, phenolic novolak resins, cresol novolak resins, aliphatic phenol resins such as dicyclopentadiene derivatives, aromatic phenol resins such as biphenyl type, naphthyl type, and bisphenol type. Is mentioned. These phenol resin curing agents may be used alone or in combination of two or more.

  The (A) component epoxy resin and the (B) component phenol resin curing agent include the epoxy group (a) of the (A) component epoxy resin and the phenolic hydroxyl group (B) of the phenol resin curing agent (B) component. It is preferable to make it contain so that ratio (a) / (b) (equivalent ratio) with b) may be in the range of 0.1 to 2.0, and so that it may be in the range of 0.5 to 1.5. More preferably. If the equivalent ratio is less than 0.1 or exceeds 2.0, the moldability, the heat resistance of the cured product, the moisture resistance and the like may be reduced.

  Examples of the inorganic filler of component (C) used in the present invention include metal oxide powders such as silica powder and alumina powder, metal nitride powders such as silicon nitride powder and aluminum nitride powder, and metal carbide powders such as silicon carbide powder. , Calcium carbonate powder, silicone powder, glass fiber and the like. These inorganic fillers may be used individually by 1 type, and 2 or more types may be mixed and used for them.

  In the present invention, it is preferable to use silica powder among the inorganic fillers described above. Specific examples of the silica powder include fused crushed silica, fused spherical silica, and crystalline silica. From the standpoints of balance of expansion coefficients, reliability when cured, and printability by laser, etc. Spherical silica is preferably used.

  The inorganic filler of component (C) preferably has an average particle size of 1 to 60 μm and a maximum particle size of 200 μm or less. When the average particle size is out of the above range or the maximum particle size is out of the above range, the moldability of the encapsulating resin composition and the marking property by laser on the cured product may be deteriorated. For the measurement of the average particle diameter of the inorganic filler, for example, a laser diffraction scattering type particle size distribution measuring apparatus can be used.

  The content of the inorganic filler of component (C) is 70 to 95% by weight, preferably 72 to 90% by weight, based on the entire sealing resin composition. If the content of the inorganic filler is less than 70% by weight, the moldability, the mechanical properties of the cured product, the heat resistance and the moisture resistance may be deteriorated, and the marking by the laser may be unclear. On the other hand, if the content exceeds 95% by weight, the bulk is increased, the fluidity of the composition is lowered, and the moldability may be deteriorated.

The fullerene of component (D) used in the present invention is a carbon allotrope composed of only carbon atoms, like carbon black and graphite, but the conductivity is different from carbon black and graphite, and is also known as a carbon allotrope. This is an insulator region. For example, the conductivity of C60 fullerene is 10 ⁻⁸ to 10 ⁻¹⁴ (Ω · cm) ⁻¹ . On the other hand, the electrical conductivity of diamond is 10 ⁻⁸ to 10 ⁻¹⁴ (Ω · cm) ⁻¹ , and the carbon black (combustion method) is 10 × 10 ⁻¹ (Ω · cm) ⁻¹ . This component is blended as a black colorant, and various types of C20 or higher, for example, C20, C24, C50, C60, C70, C76, C84, etc. are used. In addition, derivatives obtained by hydrogenation, oxidation, alkylation, amination, halogenation, cycloaddition or inclusion, or those treated with a coupling agent or the like can also be used. These may be used individually by 1 type, and may mix and use 2 or more types. In the present invention, C60 and C70 are particularly preferable.

  The fullerene of component (D) preferably has a weight average particle size of 100 μm or less, more preferably 1 to 50 μm, in consideration of the color tone and moldability in marking. When the weight average particle size exceeds 100 μm, the coloring power as a colorant is lowered, thereby reducing the contrast of the marking, which may make it difficult to perform clear marking.

  The content of the fullerene as component (D) is 0.01 to 2.0% by weight, preferably 0.06 to 0.90% by weight, based on the entire sealing resin composition. When the content of fullerene is less than 0.01% by weight, the light shielding ability of the composition is lowered, which may cause malfunction of the semiconductor device. Further, the contrast of the marking by the laser may be lowered. On the other hand, if the content exceeds 2.0% by weight, the fullerene in the portion irradiated with the laser beam at the time of marking by the laser may not be completely detached, and the contrast may be lowered.

The carbon material of component (E) used in the present invention is a component blended as a black colorant together with the fullerene of component (D), and at the same time, blended for the purpose of improving the contrast in marking by laser. It is. Similar to fullerene, this carbon material is a carbon allotrope composed of only carbon atoms, but unlike carbon black and graphite, it has a feature that there is almost no graphite structure. Specifically, it is insoluble in an organic solvent, and the strongest peak exists in the diffraction angle range of 10 to 18 ° within the diffraction angle range of 3 to 30 ° in the X-ray diffraction measurement analysis using CuKα rays. However, there is no or very small peak at a diffraction angle of 23 to 27 ° corresponding to the plane of the graphite structure. In addition, this carbon material has peaks in band G (1590 ± 20 cm ⁻¹ ) and band D (1340 ± 40 cm ⁻¹ ) in the Raman spectrum measured at an excitation wavelength of 514.5 nm, and peaks in those bands. When the intensity is I (G) and I (D), the peak intensity ratio I (D) / I (G) is in the range of 0.4 to 1.0. This means that the carbon material has a highly ordered structure although it is different from the graphite structure. The presumed structure is not a planar structure found in graphite, but is considered to be a specific internal structure having a curved unit structure derived from a carbon 5-membered ring similar to fullerene. One of the specific properties due to can be seen in the electrical conductivity, and the conductivity is 10 ⁻² to 10 ⁻⁸ (Ω · cm) ⁻¹ , which is smaller than that of carbon black.

  Here, “insoluble in an organic solvent” of the present carbon material means that the carbon material is added to 90 weight times 1,2,4-trimethylbenzene at room temperature, stirred and filtered, and then at 150 ° C. for 10 hours. The weight reduction rate when vacuum-dried is 5% or less.

  The carbon material of component (E) can be produced by a method generally called a combustion method. In other words, carbon-containing compounds are burned under specified conditions, and the resulting soot is collected from the end of the flame, the inside of the flame, the inner surface of the burner chamber, etc., and then components soluble in the organic solvent contained in the soot are extracted. It can be obtained by removing, further filtering and drying.

The carbon material of component (E) is preferably a powder having a weight average particle diameter of 100 μm or less, and more preferably a powder having a weight average particle diameter of 1 to 50 μm. When the weight average particle diameter exceeds 100 μm, the coloring power as a colorant is lowered, and as a result, the contrast of the marking is lowered, and it may be difficult to perform clear marking. Further, component (E) carbon material is preferably a nitrogen adsorption method specific surface area by (BET method) is 10 to 200 m ² / g, more preferably 12~180m ² / g. When the specific surface area is less than 10 m ² / g, the dispersibility becomes poor and the coloring power as a colorant may be reduced. On the contrary, if the specific surface area exceeds 200 m ² / g, the bulk density becomes extremely small, and the fluidity of the resin composition may be lowered.

  The content of the carbon material of component (E) is 0.01 to 2.0% by weight, preferably 0.06 to 0.90% by weight, based on the entire sealing resin composition. When the content is less than 0.01% by weight, it becomes difficult to improve the contrast of marking by a laser. On the other hand, if the content exceeds 2.0% by weight, the fluidity of the composition is lowered, which may make it unsuitable for practical use.

  As described above, in the resin composition for encapsulating a semiconductor of the present invention, the carbon material having the specific internal structure as described above is used as the black colorant, and the conductivity caused by the internal structure is used. Focusing on characteristics such as color, colorability, and laser marking properties, the conventional composition is greatly improved by making an optimal composition.

  The resin composition for encapsulating a semiconductor of the present invention comprises (A) an epoxy resin, (B) a phenol resin curing agent, (C) an inorganic filler, (D) fullerene, and (E) a carbon material described above as essential components. However, a curing accelerator generally blended in this type of composition as necessary as long as the effect of the present invention is not impaired; natural waxes, synthetic waxes, esters, linear aliphatics Mold release agents such as metal salts, acid amides, paraffins, and the like; low stress imparting agents such as rubber-based and silicone-based polymers; coupling agents as inorganic filler treating agents can be further blended. Further, a colorant such as cobalt blue can be appropriately blended within a range not impairing the effects of the present invention.

  Examples of the curing accelerator include trimethylphosphine, triethylphosphine, tributylphosphine, triphenylphosphine, tri (p-methylphenyl) phosphine, tri (nonylphenyl) phosphine, methyldiphenylphosphine, dibutylphenylphosphine, tricyclohexylphosphine, bis ( Organophosphorous curing accelerators such as diphenylphosphino) methane, 1,2-bis (diphenylphosphino) ethane, tetraphenylphosphonium tetraphenylborate, triphenylphosphinetetraphenylborate, triphenylphosphinetriphenylborane; Of diazabicycloalkene compound systems such as 8-diazabicyclo [5,4,0] undecene-7 (DBU), 1,5-diazabicyclo (4,3,0) nonene-5 2-heptadecylimidazole, 2-methylimidazole, 2-ethylimidazole, 2-phenylimidazole, 2-phenyl-4-methylimidazole, 4-methylimidazole, 4-ethylimidazole, 2-phenyl-4- Imidazoles such as hydroxymethylimidazole, 2-enyl-4-methylimidazole, 1-cyanoethyl-2-methylimidazole, 2-phenyl-4-methyl-5-hydroxymethylimidazole, 2-phenyl-4,5-dihydroxymethylimidazole And a tetraphenylboron curing accelerator such as 2-ethyl-4-methylimidazole tetraphenylborate. These curing accelerators may be used alone or in combination of two or more.

  Coupling agents include γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropylmethyldiethoxysilane, β- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, and γ- (methacrylopropyl). ) Trimethoxysilane, γ-aminopropyltrimethoxysilane, N-β- (aminoethyl) -γ-aminopropyltrimethoxysilane, N-β- (aminoethyl) -γ-aminopropylmethyldimethoxysilane, N-β -(Aminoethyl) -γ-aminopropylmethyldiethoxysilane, N-phenyl-γ-aminopropyltrimethoxysilane, γ-ureidopropyltriethoxysilane, γ-mercaptopropyltrimethoxysilane, γ-mercaptopropylmethyldimethoxysilane Bis (3-triethoxysilyl) (Lopyl) Tetrasulfane, methyltrimethoxysilane, methyltriethoxysilane, vinyltrimethoxysilane, vinyltriacetoxysilane, imidazolesilane, and other silane coupling agents are listed. Others include titanium coupling agents and aluminum alcoholates. Etc. can also be used. These coupling agents may be used alone or in combination of two or more.

  The resin composition for semiconductor encapsulation of the present invention includes (A) an epoxy resin, (B) a phenol resin curing agent, (C) an inorganic filler, (D) fullerene, and (E) a specific carbon material, as described above. By mixing the various components to be blended uniformly with a mixer, etc., and further heat-melting and kneading with a hot roll or kneader, etc., cooling and solidifying, and then grinding to an appropriate size Prepared.

  Further, (D) fullerene and (E) specific carbon material are previously mixed with at least a part, preferably all, of (A) an epoxy resin and / or (B) a phenol resin curing agent, heated and melted and kneaded. You may make it mix the obtained preliminary kneaded material with another component. By using such a preliminary kneaded product, the moldability and reliability can be further improved. A release agent, other colorant, coupling agent and the like can be appropriately added to the pre-kneaded product.

  The semiconductor device of the present invention can be easily manufactured by sealing a semiconductor element using the above-described sealing resin composition. The semiconductor element is not particularly limited, and examples thereof include an integrated circuit, a large-scale integrated circuit, a transistor, a thyristor, and a diode. The most common method for sealing semiconductor elements is the low-pressure transfer molding method, but sealing by injection molding, compression molding, casting, or the like is also possible. By molding, the filling property into the gap can be further improved. The sealing resin composition is heated and cured at the time of sealing, and the temperature at this time is preferably 150 ° C. or higher.

  For such a semiconductor device, the marking resin portion can be marked using a carbon dioxide laser, a YVO4 laser, a YAG laser, an excimer laser, or the like. Marking with various lasers can be performed using the same method as before, and is not particularly limited. Since the semiconductor device of the present invention is encapsulated with the encapsulating resin composition as described above, sufficient contrast can be obtained even if marking is performed using the same method as before, and clear marking can be performed. it can.

  Next, specific examples of the present invention will be described, but the present invention is not limited to these examples.

Examples 1-7, Comparative Examples 1-4
C60 fullerene (manufactured by Frontier Carbon Co., Ltd., trade name: Nanom Purple; weight average particle diameter 20 μm), carbon powder (manufactured by Frontier Carbon Co., Ltd., trade name: Nanom Black; weight average particle diameter 20 μm), carbon black (Mitsubishi Chemical Corporation) Product name MA-600; average particle size 20 nm) and o-cresol novolac resin (Sumitomo Chemical Co., Ltd. product name EOCN-195XL-70; epoxy equivalent 198), phenol novolac resin (Showa Polymer Co., Ltd.) Product name BRG-557; hydroxyl group equivalent 105), fused spherical silica powder (trade name FB-60 manufactured by Denki Kagaku Kogyo Co., Ltd., average particle size 23 μm), carnauba wax (product name, Toyo Petrolite Co., Ltd.) Wax), coupling agent (trade name A-187 manufactured by Nippon Unicar Co., Ltd.) and curing acceleration (Product name: PP-200, manufactured by Hokuko Chemical Co., Ltd.) was mixed at room temperature using a mixer with the composition shown in Table 1, and heated and kneaded at a temperature of 90 to 95 ° C with a pressure kneader, and then cooled and solidified. Furthermore, the resin composition for sealing was manufactured by pulverizing to an appropriate particle size.

  In Example 7, fullerene (Nanomu Purple) and carbon powder (Nanomu Black) were previously kneaded with o-cresol novolac resin (total amount) to prepare a pre-kneaded product, which was combined with other components. Mixed. That is, fullerene (Nanomu Purple), carbon powder (Nanomu Black) and o-cresol novolac resin (total amount) are mixed at room temperature using a mixer, heated and kneaded at a temperature of 90 to 95 ° C. with a pressure type kneader, and then cooled. The mixture was solidified and further pulverized to an appropriate particle size to obtain a pre-kneaded product. Next, the preliminary kneaded product and other components are mixed at room temperature using a mixer, heated and kneaded at a temperature of 90 to 95 ° C. with a pressure kneader, cooled and solidified, and further pulverized to an appropriate particle size. A sealing resin composition was produced.

  The sealing resin compositions obtained in Examples 1 to 7 and Comparative Examples 1 to 4 were transfer-molded under the conditions of 175 ° C. × 2 minutes, and further post-cured at 175 ° C. for 8 hours to obtain a thickness of 1 A molded product for test of 0.0 mm was obtained. Further, resin sealing was performed on the semiconductor chip under the same conditions, and a QFP 256-pin package (28 mm × 28 mm × 1.4 mm, 50 μm between wires) was produced.

  About each said molded article for a test, while measuring the external appearance and laser marking property by the method shown below, the light transmittance was measured. Moreover, the insulation reliability was evaluated by the method shown below about the semiconductor package sealed with resin. Furthermore, about each said resin composition for sealing, spiral flow was measured and the moldability was evaluated. These results are shown in the lower column of Table 1.

[appearance]
The color of the appearance of the test molded product was visually observed. Then, the appearance was evaluated according to the following criteria.
○: Good △: Slightly good (no problem in practical use)
×: Defect (those with practical problems)
[Laser marking properties]
Using a YAG laser marking device manufactured by Keyence Corporation, marking is performed under the conditions of output 14A, frequency 5.0 kHz, marking speed 400 mm / s, and character line width 0.2 mm, and visually observe the contrast of the marking characters. Evaluation was made according to the following criteria.
○: Marking character is white △: Marking character color is the intermediate color between the appearance of the molded product and white ×: Marking character color is the same color as the appearance of the molded product Also, measure and set the line width of the marking character The ratio (%) to the value (0.2 mm) was determined. And the laser marking property was evaluated according to the following criteria.
○: Good △: Slightly good (no problem in practical use)
×: Defect (those with practical problems)
[Light transmittance]
Using a spectrophotometer V-570 manufactured by JASCO Corporation, the light transmittance with a thickness of 1 mm was measured in the wavelength region of 300 to 800 nm.
[Insulation reliability]
A continuity test was conducted to examine the presence or absence of leakage between pads, and evaluation was performed according to the following criteria.
○: No leak ×: Leak [formability]
Using a spiral flow mold according to EMMI-1-66, the encapsulating resin composition was transferred and cured into a spiral flow mold heated to 175 ° C., and the flowed length was measured.

  As is clear from the results in Table 1, the sealing resin compositions of the examples are excellent in moldability, and in molded articles using the same, the appearance is good and the marking performance by laser is also excellent. Admitted. Furthermore, the semiconductor package encapsulated with the encapsulating resin composition of the example was also free from leakage defects and excellent in insulation reliability.

Claims (6)

(A) epoxy resin, (B) phenol resin curing agent, (C) inorganic filler, (D) fullerene, and (E) insoluble in organic solvents, and in the X-ray diffraction measurement analysis using CuKα rays A resin composition for encapsulating a semiconductor containing a carbon material having a strongest peak within a range of 3 to 30 ° and a diffraction angle of 10 to 18 °,
70 to 95% by weight of the component (C), 0.01 to 2.0% by weight of the component (D), and 0.01 to the component (E) with respect to the entire resin composition for semiconductor encapsulation. The resin composition for semiconductor sealing characterized by containing -2.0weight%.   2. The resin composition for semiconductor encapsulation according to claim 1, wherein the fullerene as the component (D) contains C60 fullerene and / or C70 fullerene. The carbon material of component (E) has peaks in band G (1590 ± 20 cm ⁻¹ ) and band D (1340 ± 40 cm ⁻¹ ) in the Raman spectrum at an excitation wavelength of 514.5 nm, and the peak in each band The peak intensity ratio I (D) / I (G) is 0.4 to 1.0 when the intensity is I (G) and I (D), respectively. Semiconductor sealing resin composition. The resin composition for semiconductor encapsulation according to any one of claims 1 to 3 , wherein the inorganic filler of the component (C) contains silica powder. Including a pre-kneaded product of the fullerene of the component (D) and the carbon material of the component (E), and the epoxy resin of the component (A) and / or at least a part of the phenol resin curing agent (B). The resin composition for semiconductor encapsulation according to any one of claims 1 to 4 , wherein the resin composition is for semiconductor encapsulation. A semiconductor device comprising a semiconductor element sealed with a cured product of the resin composition for sealing a semiconductor according to any one of claims 1 to 5 .