Liquid compression molding material, cured product, electronic component, and semiconductor device

Abstract

The present invention provides excellent visibility of a printed part formed by laser marking. This liquid compression molding material comprises (A) an epoxy resin, (B) a curing agent, (C) an inorganic filler, and (D) a coloring material, wherein the absorbance measured under the following absorbance measurement conditions using a photometer is 3.5 or more. (Absorbance measurement conditions) Measurement sample: a cured product obtained by curing the liquid compression molding material through a heat treatment at 150°C for 60 minutes. Thickness of measurement sample: 260 μm Measurement wavelength: 1064 nm

Description

Liquid compression molding materials, cured products, electronic components and semiconductor devices

[0001] The present invention relates to liquid compression molding materials, cured products, electronic components, and semiconductor devices.

[0002] Many semiconductor elements, such as integrated circuits that make up semiconductor devices, are sealed with encapsulating materials. There are broadly two types of molding methods for encapsulating semiconductor elements: (i) transfer molding, in which a molten curable resin composition is injected under pressure into a cavity through a channel that supplies resin compositions such as runners and gates into the cavity, and then cured; and (ii) compression molding, in which a granular or liquid curable resin composition is supplied directly onto a substrate or release film without going through channels such as runners and gates, and then cured. Of these molding methods, compression molding, which is relatively more suitable for manufacturing larger molded products, has recently been increasingly adopted as a molding method for encapsulating semiconductor elements. This is due to the increasing popularity of wafer-level chip-size packages (packages that employ a processing process to encapsulate wafers in a state where they have not been cut into chips after circuit formation is complete) as a packaging method for semiconductor elements. In addition, when encapsulating various elements such as semiconductor elements using encapsulating materials, organic substrates are sometimes used instead of wafers made of inorganic materials such as silicon as the substrate.

[0003] Conventional curable resin compositions used for encapsulating various elements such as semiconductor devices by compression molding were mainly solid resin compositions, such as granular ones. However, recently, with the development of new compression molding technologies, liquid curable resin compositions (so-called liquid compression molding materials) are increasingly being used. Hereinafter, liquid compression molding materials may be abbreviated as "LCM (Liquid Compression Molding) material".

[0004] On the surface of a sealed article obtained by curing an LCM material supplied to cover various elements, various identification information such as a production lot number, a logo mark, etc. is printed. As one method of printing on the surface of a sealant layer (a layer made of a cured product of an LCM material) provided to cover the surface portion of the sealed article, a laser marking method is known. The laser marking method is a technique for performing printing by scraping off the surface of the sealant layer with laser light. According to the laser marking method, since the sealant layer is directly engraved, additional processes such as cleaning are unnecessary, the production efficiency is higher than that of the printing method, and the durability of the printed portion is improved. In addition, for printing by the laser marking method, an LCM material containing a coloring material such as carbon black is usually used (for example, see Patent Document 1).

[0005] Japanese Patent Application Laid-Open No. 2014-152314

[0006] Therefore, when laser marking is performed on a sealed article produced using an LCM material containing a coloring material, the LCM material is required to be excellent in the visibility of the printed portion.

[0007] In addition, lasers used for laser marking are roughly classified into three types: an IR laser in the infrared region, a green laser in the visible light region, and a UV laser in the ultraviolet region from the viewpoint of the wavelength of the laser light. Since UV lasers and green lasers have a shorter wavelength compared to IR lasers, they have the merit of having high energy applied to the sealant layer and excellent printability. On the other hand, IR lasers have the merit of low equipment introduction costs. For this reason, especially from the perspective of users of LCM materials who emphasize cost reduction of equipment, the LCM material is required to have excellent visibility even in laser marking using an IR laser with a longer wavelength and lower introduction costs than UV lasers and green lasers that are easier to print.

[0008] On the other hand, to suppress warping of the sealed article, LCM material usually contains a large amount of inorganic filler. However, the large amount of inorganic filler present in the sealant layer (which consists of cured LCM material) reduces the adhesive strength at the interface between the sealant layer and the element, making the sealed article more prone to delamination defects. For this reason, LCM material is also required to have excellent adhesive strength in the sealed article made using it.

[0009] The present invention has been made in view of the above circumstances. The first aspect of the present invention aims to provide a liquid compression molding material with excellent visibility of printed portions formed by laser marking, a cured product thereof, and electronic components and semiconductor devices containing the cured product. The second aspect of the present invention aims to provide a liquid compression molding material with excellent visibility of printed portions formed by laser marking and excellent adhesive strength in sealed articles, a cured product thereof, and electronic components and semiconductor devices containing the cured product.

[0010] The above problem is solved by the present invention as follows. Specifically, the liquid compression molding material of the present invention comprises (A) epoxy resin, (B) curing agent, (C) inorganic filler, and (D) coloring agent, and the absorbance measured using a photometer under the following absorbance measurement conditions is 3.5 or higher. (Absorbance measurement conditions) - Measurement sample: Cured product obtained by heating the liquid compression molding material at 150°C for 60 minutes - Thickness of measurement sample: 260 μm - Measurement wavelength: 1064 nm

[0011] In the first embodiment of the present invention, it is preferable that the (D) coloring agent includes carbon black or black titanium oxide.

[0012] In another embodiment of the first invention, it is preferable that the (D) coloring agent comprises at least carbon black.

[0013] In another embodiment of the first invention, it is preferable that the content of the coloring agent (D) is 0.1% by mass to 5.0% by mass.

[0014] The second aspect of the present invention comprises (A) epoxy resin, (B) curing agent, (C) inorganic filler, and (D1) carbon black, wherein the content of (D1) carbon black is 0.1% by mass to 5.0% by mass.

[0015] In the first embodiment of the present invention and the second embodiment of the present invention, it is preferable that the oil absorption amount per 100 g of carbon black is 100 to 200 ml / 100 g.

[0016] Other embodiments of the first and second inventions preferably further include a curing accelerator.

[0017] In the first and second embodiments of the present invention, it is preferable that the content of the inorganic filler (C) is 55% to 85% by mass.

[0018] The cured product of the present invention is a cured product of the first or second liquid compression molding material of the present invention.

[0019] The electronic component of the present invention includes the cured product of the present invention.

[0020] The semiconductor device of the present invention includes the cured product of the present invention.

[0021] According to the first aspect of the present invention, it is possible to provide a liquid compression molding material with excellent visibility during laser marking, a cured product thereof, and electronic components and semiconductor devices containing the cured product. Furthermore, according to the second aspect of the present invention, it is possible to provide a liquid compression molding material with excellent visibility during laser marking and adhesive strength in sealed articles, a cured product thereof, and electronic components and semiconductor devices containing the cured product.

[0022] <LCM Material (First Embodiment)> The LCM material of the first embodiment comprises (A) epoxy resin, (B) curing agent, (C) inorganic filler, and (D) coloring agent, and the absorbance measured using a photometer under the following absorbance measurement conditions is 3.5 or higher. (Absorbance Measurement Conditions) - Measurement sample: Cured product obtained by heating the liquid compression mold material at 150°C for 60 minutes - Thickness of measurement sample: 260 μm - Measurement wavelength: 1064 nm

[0023] In the LCM material of the first embodiment, the absorbance of the cured product in the infrared region is 3.5 or higher, so even when laser marking is performed using an IR laser, which tends to be more difficult to print with compared to UV lasers and green lasers, excellent visibility can be obtained. From the viewpoint of obtaining even better visibility, an absorbance of 3.7 or higher is preferable, 4.0 or higher is more preferable, and 4.5 or higher is even preferable. On the other hand, there is no particular upper limit to the absorbance, but in order to increase the absorbance, it is necessary to blend more coloring agent into the LCM material, and the blending of excessive coloring agent increases the possibility of causing some kind of problem. For practical purposes, an absorbance of 10 or less is preferable, 9 or less is more preferable, and 8 or less is even preferable. As mentioned above, the LCM material of the first embodiment is particularly effective in improving the visibility of the printed part when using an IR laser, but when performing laser marking on a sealed article made using this LCM material, lasers of other wavelength ranges such as UV lasers and green lasers can of course be used in addition to IR lasers.

[0024] Next, the details of each component used in the LCM material of the first embodiment will be described below.

[0025] (A) Epoxy resin The epoxy resin used in the LCM material is not particularly limited as long as it is one of the various epoxy resins generally used for semiconductor encapsulation. However, from the viewpoint of viscosity and injectability, it is preferable to use a liquid epoxy resin for the LCM material. Furthermore, as the epoxy resin blended into the LCM material, only one type of epoxy resin may be used, or two or more types of epoxy resins may be used in combination.

[0026] Typical examples of epoxy resins include aromatic epoxy resins and aliphatic epoxy resins. Examples of aromatic epoxy resins include bisphenol A type epoxy resins such as p-glycidyloxyphenyldimethyltrisbisphenol A diglycidyl ether; bisphenol F type epoxy resins; novolac type epoxy resins; fluorene type epoxy resins; biphenyl aralkyl epoxy resins; diepoxy resins such as p-tert-butylphenyl glycidyl ether and 1,4-phenyldimethanol diglycidyl ether; biphenyl type epoxy resins such as 3,3',5,5'-tetramethyl-4,4'-diglycidyloxybiphenyl; aminophenol type epoxy resins such as diglycidylaniline, diglycidyltoluidine, triglycidyl-p-aminophenol, and tetraglycidyl-m-xylylenediamine; naphthalene type epoxy resins; and epoxy resins with plant-derived skeletons, but are not limited to these.

[0027] Furthermore, examples of aliphatic epoxy resins include specific aliphatic epoxy compounds such as alkyl alcohol glycidyl ethers [butyl glycidyl ether, 2-ethylhexyl glycidyl ether, etc.] and alkenyl alcohol glycidyl ethers [vinyl glycidyl ether, allyl glycidyl ether, etc.], which are monofunctional aliphatic epoxy compounds having one epoxy group in the molecule; polyalkylene glycol diglycidyl ethers such as alkylene glycol diglycidyl ether and polytetramethylene glycol diglycidyl ether; and alkenylene glycol diglycidyl ether. Examples include difunctional aliphatic epoxy compounds having two epoxy groups in the molecule, such as trimethylolpropane triglycidyl ethers; polyfunctional aliphatic epoxy compounds having three or more epoxy groups in the molecule, such as trimethylolpropane triglycidyl ethers, pentaerythritol, dipentaerythritol, etc. [trimethylolpropane triglycidyl ether, pentaerythritol (tri or tetra)glycidyl ether, dipentaerythritol (tri, tetra, penta or hexa)glycidyl ether, etc.], and polyether-type epoxy resins.

[0028] Among the epoxy resins exemplified above, liquid bisphenol-type epoxy, liquid naphthalene-type epoxy, liquid aminophenol-type epoxy, and polyether-type epoxy are preferred from the viewpoint of workability and injectionability.

[0029] Furthermore, the epoxy resin content relative to the total amount of LCM material is preferably 5% to 40% by mass, more preferably 5% to 30% by mass, and even more preferably 8% to 25% by mass.

[0030] (B) Curing agent The curing agent to be incorporated into the LCM material is not particularly limited as long as it is one of the various curing agents commonly used for semiconductor encapsulation, but it is preferable to use phenolic curing agents, acid anhydride curing agents, etc. One type of curing agent may be used alone, or two or more types may be used in combination.

[0031] Specific examples of phenolic curing agents include monomers, oligomers, or polymers having phenolic hydroxyl groups, such as phenol novolac resins and their alkylated or allylated derivatives, cresol novolac resins, phenol aralkyl (containing phenylene and biphenylene skeletons) resins, naphthol aralkyl resins, triphenolmethane resins, and dicyclopentadiene-type phenolic resins. Furthermore, as the phenolic curing agent incorporated into the LCM material, only one type of phenolic curing agent may be used, or two or more types of phenolic curing agents may be used in combination. In addition, from the viewpoint of workability and injectionability, a phenolic curing agent that is liquid at 25°C is preferred.

[0032] Specific examples of acid anhydride-based curing agents include alkylated tetrahydrophthalic anhydrides such as methyltetrahydrophthalic anhydride and methylhexahydrophthalic anhydride, hexahydrophthalic anhydride, methylhymic anhydride, succinic anhydride substituted with alkenyl groups, methylnadic anhydride, and glutaric anhydride. Furthermore, when using an acid anhydride-based curing agent in an LCM material, only one type of acid anhydride-based curing agent may be used, or two or more types of acid anhydride-based curing agents may be used in combination. Among the acid anhydride-based curing agents listed above, methyltetrahydrophthalic anhydride and methylhexahydrophthalic anhydride are preferred from the viewpoint of having excellent electrical insulation properties, heat stability, and being liquid at room temperature (25°C).

[0033] In the LCM material of the first embodiment, it is particularly preferable to use a combination of (B1) a phenolic curing agent and (B2) an acid anhydride curing agent as (B) curing agents. In this case, there are no particular restrictions on the mixing ratio of (B1) a phenolic curing agent and (B2) an acid anhydride curing agent, but the ratio of the phenol equivalent b1 of (B1) a phenolic curing agent to the acid anhydride equivalent b2 of (B2) an acid anhydride curing agent, i.e., the equivalent ratio b1:b2, is preferably 10:90 to 90:10, more preferably 15:85 to 85:15, even more preferably 35:65 to 80:20, particularly preferably 45:55 to 80:20, and most preferably 45:55 to 55:45. Note that the phenol equivalent b1 is calculated as the mass of component (B1) / the hydroxyl group equivalent in component (B1), and the acid anhydride equivalent b2 is calculated as the mass of component (B2) / the acid anhydride group equivalent in component (B2).

[0034] When the equivalent ratio b1:b2 is set within the range of 10:90 to 90:10, (i) it becomes easier to ensure the excellent rapid curing properties of the LCM material, and (ii) it becomes easier to adjust the glass transition temperature Tg of the cured product within the range of 50°C to 120°C, thus making it easier to suppress warping of sealed articles such as semiconductor devices made using LCM material. The reason why effect (ii) is obtained is as follows. First, generally, the elastic modulus of a cured resin composition changes significantly with respect to the glass transition temperature Tg. In the temperature range below the glass transition temperature Tg where the cured product is in a glassy state, it has a relatively very high elastic modulus, and in the temperature range above the glass transition temperature Tg where the cured product is in a rubbery state, it has a relatively very low elastic modulus. On the other hand, in a compression molding process using LCM material, the heating temperature during molding and the heating temperature during post-curing performed after molding are usually carried out at temperatures exceeding around 130°C. Therefore, by setting the glass transition temperature Tg of the cured material to 120°C or lower, the elastic modulus of the cured material near the heating temperature during molding and post-curing can be made very low. This reduces internal stress caused by differences in the degree of shrinkage of each component constituting the sealed article during the cooling process after heating, and consequently suppresses warping of the sealed article. The glass transition temperature Tg can be measured by the DMA (Dynamic Mechanical Analysis) method.

[0035] The mass ratio of (B1) phenol-based curing agent and (B2) acid anhydride-based curing agent is not particularly limited as long as the equivalent ratio b1:b2 can be adjusted to within the range of 10:90 to 90:10. However, the mass ratio is usually preferably 10:90 to 90:10, more preferably 15:85 to 85:15, and even more preferably 35:65 to 80:20.

[0036] Furthermore, the content of (B) curing agent in the total resin composition constituting the LCM material is preferably 2% by mass or more, more preferably 5% by mass or more, and even more preferably 8% by mass or more, from the viewpoint of ensuring sufficient curability. On the other hand, there is no particular upper limit to the content, but from the viewpoint of balancing the blend with other components blended into the resin composition, it is practically preferable to have 50% by mass or less, more preferably 30% by mass or less, and even more preferably 20% by mass or less.

[0037] (C) Inorganic filler The inorganic filler can be any inorganic material that has the effect of reducing the thermal expansion coefficient of the cured LCM material, and is not particularly limited. Specific examples of inorganic fillers include silica, alumina, aluminum, aluminum nitride, silicon carbide, silicon nitride, boron nitride, magnesium oxide, etc. From the viewpoint of being able to increase the amount of inorganic filler added to the LCM material (filling amount), silica or alumina is particularly preferred as the inorganic filler. The inorganic filler may also be surface-treated with a surface treatment agent such as a silane coupling agent. Furthermore, as the inorganic filler added to the LCM material, only one type of inorganic filler may be used, or two or more types of inorganic fillers may be used in combination.

[0038] The shape of the inorganic filler is not particularly limited and may be spherical, amorphous, flake-shaped, or any other form. The average particle size of the inorganic filler is preferably 0.001 μm to 10 μm, more preferably 0.005 μm to 7 μm, even more preferably 0.01 μm to 5 μm, and particularly preferably 0.03 μm to 3 μm. The average particle size refers to the volume average particle size D50 value (the particle size that represents 50% of the cumulative distribution from the smallest diameter side of the volume-based particle size distribution) measured using a laser diffraction particle size distribution analyzer.

[0039] Furthermore, from the viewpoint of further reducing the viscosity of the LCM material while maintaining a high content of inorganic fillers, it is preferable to use a combination of two types of inorganic fillers with different volume average particle sizes D50. In this case, the ratio of the volume average particle size D50 (DL) of the large-diameter inorganic filler to the volume average particle size D50 (DS) of the small-diameter inorganic filler (DL / DS) is preferably 4 to 30, more preferably 8 to 15, and the ratio of the content AL of the large-diameter inorganic filler incorporated into the LCM material to the content AS of the small-diameter inorganic filler incorporated into the LCM material (AL / AS) is preferably 1 to 5, more preferably 2 to 4.

[0040] The inorganic filler content relative to the total amount of LCM material is preferably 55% to 85% by mass, more preferably 65% ​​to 85% by mass, even more preferably 65% ​​to 80% by mass, and particularly preferably 70% to 77% by mass. Setting the inorganic filler content to 85% by mass or less makes it easier to ensure appropriate low viscosity and injectability as an LCM material, and also improves the adhesive strength at the bonding interface between the sealing material layer constituting the sealed article and the element, etc. Furthermore, setting the inorganic filler content to 55% by mass or more makes it easier to suppress warping of the sealed article.

[0041] (D) Coloring materials As coloring materials, known black or dark coloring materials can be used. Specifically, examples include (D1) carbon black, (D2) black titanium oxide, black chromium oxide, phthalocyanine pigments, perylene pigments, and other known black or dark pigments, and (D3) azine dyes, azo dyes, and other known black or dark dyes.

[0042] From the viewpoint of improving the visibility of the printed area formed by laser marking, the content of the coloring agent relative to the total amount of LCM material is preferably 0.1% by mass or more, and more preferably 0.2% by mass or more. Furthermore, there is no particular upper limit to the content of the coloring agent, but as the content of the coloring agent increases, the effect of improving visibility tends to decrease or saturate, so in practical terms, 5.0% by mass or less is preferred, 4.0% by mass or less is more preferred, 3.5% by mass or less is even more preferred, and 3.0% by mass or less is particularly preferred. Also, from a similar viewpoint, the content of the coloring agent relative to the total amount of (A) epoxy resin is preferably 0.7% by mass or more, more preferably 2.0% by mass or more, even more preferably 5.0% by mass or more, particularly preferred 10.0% by mass or more, preferably 50.0% by mass or less, more preferably 40.0% by mass or less, even more preferably 30.0% by mass or less, and particularly preferred 27.0% by mass or less. Furthermore, when at least carbon black is used as a coloring agent, it is preferable that the suitable range of carbon black content relative to the total amount of LCM material be the same as that of the LCM material of the second embodiment described later.

[0043] The coloring material may be used alone or in combination of two or more kinds. From the viewpoint of a large increase in absorbance per unit mass of the coloring material and a great effect of improving visibility, it is preferable to use at least carbon black as the coloring material. In addition, carbon black also has an effect of improving the adhesive strength of the bonding interface between the sealing material layer and the element or the like that constitutes the sealed article. Further, from the viewpoint of ensuring excellent visibility and further improving the insulation of the sealed article, it is also preferable to use titanium black oxide as the coloring material. In view of these points, it is preferable to use carbon black and / or titanium black oxide as the coloring material, and it is more preferable to use carbon black. The oil absorption amount of the carbon black used as the coloring material is not particularly limited, but for example, it can be 100 to 200 ml / 100 g. Further, when two or more kinds of coloring materials are used in combination, for example, it is also suitable to use a combination of carbon black and titanium black oxide. In this case, the ratio of the content of carbon black to titanium black oxide is preferably 10:90 to 90:10, more preferably 20:80 to 90:10, and even more preferably 30:70 to 90:10.

[0044] (E) Other components In the LCM material of the first embodiment, (E) other components other than the above components (A) to (D) may be further blended as needed. The other components are not particularly limited, but for example, alcohol compounds such as polyether polycarbonate diol, curing accelerators, coupling agents, ion trappers, leveling agents, antioxidants, defoaming agents, flame retardants, reactive diluents, elastomers, etc. can be mentioned. Further, the blending amount of the other components can be appropriately selected according to the type thereof.

[0045] In addition, when other components (E) are blended into the LCM material, it is preferable to blend a curing accelerator among the other components listed above. Specific examples of the curing accelerator include imidazoles, salts of triphenylphosphine or tetraphenylphosphine, modified imidazole compounds, and the like. Specifically, 2-methylimidazole, 2-ethylimidazole, 2-phenylimidazole, 2-phenyl-4-methylimidazole, 2-phenyl-4-methyl-5-hydroxymethylimidazole, 2-phenyl-4,5-dihydroxymethylimidazole, 2,4-diamino-6-(2'-methylimidazolyl-(1'))-ethyl-s-triazine isocyanuric acid adduct, epoxy-imidazole adduct compounds, acrylate-imidazole adduct compounds, etc. may be mentioned. Further, as the curing accelerator blended into the LCM material, only one kind may be used, or two or more kinds of curing accelerators may be used in combination. From the viewpoint of pot life, acrylate-imidazole adduct compounds are preferable as the curing accelerator.

[0046] The content of the curing accelerator with respect to the total amount of the LCM material is preferably 0.1% by mass to 5.0% by mass, more preferably 0.3% by mass to 4.0% by mass, and even more preferably 0.5% by mass to 3.0% by mass.

[0047] The viscosity of the LCM material of the first embodiment at 25°C is not particularly limited, but from the viewpoint of handleability, it is preferably 10 Pa·s or more, more preferably 30 Pa·s or more, and even more preferably 50 Pa·s or more. Also, from the viewpoint of injectability, it is preferably 500 Pa·s or less, more preferably 400 Pa·s or less, and even more preferably 300 Pa·s or less.

[0048] <LCM Material (Second Embodiment)> The LCM material of the second embodiment contains (A) an epoxy resin, (B) a curing agent, (C) an inorganic filler, and (D1) carbon black, and the content of (D1) carbon black is 0.1% by mass to 5.0% by mass.

[0049] In the LCM material of the second embodiment, at least (D1) carbon black is used as the (D) coloring agent. The carbon black content relative to the total amount of LCM material is set to 0.1% by mass to 5.0% by mass. By setting the carbon black content to 0.1% by mass or more, the visibility of the printed part formed by laser marking and the adhesive strength of the sealed article can be improved. Furthermore, from the viewpoint of obtaining better visibility and adhesive strength, the carbon black content is preferably 0.25% by mass or more, more preferably 0.6% by mass or more, and even more preferably 1.2% by mass or more, from the viewpoint of obtaining even better adhesive strength. On the other hand, from the viewpoint of visibility and adhesive strength, there is no particular upper limit to the carbon black content, but if a large amount of carbon black is blended into the LCM material, the insulating properties of the sealed article tend to decrease, so in practice it is 5.0% by mass or less, preferably 4.0% by mass or less, and more preferably 3.0% by mass or less.

[0050] In the LCM material of the second embodiment, (D) only carbon black may be used as the coloring agent, or other coloring agents may be used in combination with carbon black as needed. In addition, the same coloring agents used in combination with carbon black as those used in the LCM material of the first embodiment can be used.

[0051] Furthermore, in the LCM material of the second embodiment, components (A) to (C) can be the same as those used in the LCM material of the first embodiment, and the suitable materials and content for each component can also be the same as those of the LCM material of the first embodiment. In addition, in the LCM material of the second embodiment, in addition to components (A) to (C) and component (D1), component (D) (excluding component (D1)) and / or component (E) may be appropriately blended as needed. Component (E) can be the same as the other components used in the LCM material of the first embodiment, and the suitable materials, content, viscosity, etc. can also be the same as those of the LCM material of the first embodiment.

[0052] <Method for manufacturing LCM material> The LCM material of the first embodiment is prepared by mixing and stirring components (A) to (D) (and component (E) used as needed), and the LCM material of the second embodiment is prepared by mixing and stirring components (A) to (C) and (D1) (and component (D) (excluding component (D1)) and / or component (E) used as needed).

[0053] When mixing and stirring, known mixing and stirring means such as roll mills and planetary mixers can be used as appropriate. If the epoxy resin of component (A) is solid, it is preferable to mix it in a liquefied or fluidized state by heating or the like. Furthermore, when mixing each component that constitutes the LCM material, the mixing procedure is not particularly limited. For example, all components used in the preparation of the LCM material may be mixed simultaneously, or some of the components may be mixed first, and the remaining components may be mixed afterward. If it is difficult to uniformly disperse the inorganic filler of component (C) in the epoxy resin of component (A), the epoxy resin of component (A) and the inorganic filler of component (C) may be mixed first, and then the remaining components may be mixed.

[0054] <Cured Products, Electronic Components, and Semiconductor Devices> The LCM materials of the first and second embodiments become cured products through heat treatment during compression molding. The electronic components and semiconductor devices of this embodiment, manufactured through a compression molding process using the LCM material of the first or second embodiment, include this cured product, and a sealing layer made of the cured product is provided to cover all or part of the surface of these devices. The semiconductor device of this embodiment typically includes a substrate, a semiconductor element placed on the substrate, and a cured product of the LCM material of the first or second embodiment that seals the gap between the semiconductor element and the substrate and covers at least the surface of the semiconductor element. When laser marking is performed, printing can be done by irradiating the surface of the sealing layer constituting the surface portion of the electronic component or semiconductor device with laser light.

[0055] The present invention will be described below with reference to examples, but the present invention is not limited to these examples.

[0056] 1. Preparation of LCM Material The LCM material for each example and comparative example was prepared by mixing and stirring the raw materials using a roll mill to the proportions shown in Tables 1 and 2. Details of each component used as a raw material are as follows. The proportions of each component shown in the table are in parts by mass.

[0057] 2. Raw material components used in the preparation of LCM material (A) Epoxy resins: YDF-870GS (Bisphenol F type epoxy resin: manufactured by Nippon Steel Chemical & Material, epoxy equivalent: 163 g / eq) HP-4032D (Naphthalene type epoxy resin: manufactured by DIC, epoxy equivalent: 140 g / eq)

[0058] (B) Curing agent: MEH8000H (liquid phenol novolac resin: manufactured by UBE, hydroxyl group equivalent: 135 g / eq) and MH700 (mixture of 4-methylhexahydrophthalic anhydride and hexahydrophthalic anhydride: manufactured by Shin Nippon Rika, acid anhydride group equivalent: 163 g / eq)

[0059] (C) Inorganic fillers: SE2200-SME (methacrylic surface-treated silica filler, average particle size 0.5 μm, manufactured by Admatex), YA050C-SM1 (methacrylic surface-treated silica filler, average particle size 0.05 μm, manufactured by Admatex), SE101G-SMO (methacrylic surface-treated silica filler, average particle size 0.3 μm, manufactured by Admatex)

[0060] (D) Colorants: (D1) Carbon Black: Special Black 4 (Oil absorption capacity 115 ml / 100 g, manufactured by Orion Engineered Carbons) (D2) Black Titanium Oxide: 13M (manufactured by Mitsubishi Materials) (D3) Azin-based dye: PC5856 (manufactured by Orient Chemical Industry)

[0061] (E) Other ingredients: HX-3088FR (Core-shell type curing accelerator: manufactured by Asahi Kasei)

[0062] 3. Various Measurements and Evaluations The LCM material of each example and comparative example, or the evaluation samples prepared using it, were measured and evaluated for absorbance, visibility, adhesive strength, warpage, and dielectric breakdown voltage. The results are shown in Tables 1 and 2, and the details of these measurement and evaluation methods are described below.

[0063] 3.1 Absorbance As a sample for absorbance measurement, a cured material (length x width: 30 mm x 40 mm, thickness: 260 μm) was prepared by heat treatment of LCM material at 150°C for 60 minutes. Subsequently, the absorbance of this sample was measured using a UV-Vis spectrophotometer V-670 (manufactured by JASCO Corporation). The details of the measurement conditions are as follows: • Bandwidth: 2.0 nm • Scanning speed: 400 nm / min • Near-infrared bandwidth: 8.0 nm • Wavelength: 1064 nm

[0064] 3.2 Visibility The visibility of the printed area when printed by the laser marking method was evaluated using the following procedure. First, compression molding was performed using a compression molding apparatus (TOWA Corporation, CPM1080). For compression molding, the upper and lower molds in the compression molding apparatus were first heated to 150°C, and then an FR4 substrate (GN74240, Globalnet Corporation) measuring 74 mm in length, 240 mm in width, and 300 μm in thickness was placed in the upper mold. Next, LCM material was applied to the release film, and the release film was placed in the lower mold in the compression molding apparatus with the side coated with LCM material facing upwards. After that, the lower mold was operated, and compression molding was performed at 150°C / 300 seconds to obtain a cured product (67 mm in length, 233 mm in width, and 260 μm in thickness) formed on the FR4 substrate. After the compression molding was completed, the FR4 substrate with the cured product formed was removed from the mold and placed in a dryer set to 180°C for 1 hour. This resulted in obtaining a test specimen in which a layer made of cured LCM material was formed on one side of the FR4 substrate.

[0065] Next, the letters "TEG" were printed on the surface of the cured material layer of 10 test pieces prepared for each example and comparative example using a laser processing machine. After printing, the printed areas were visually inspected, and the visibility was evaluated according to the following criteria: A: No test pieces had missing or unrecognizable printed letters. B: One test piece had missing or unrecognizable printed letters. C: Two or more test pieces had missing or unrecognizable printed letters.

[0066] The visibility was evaluated using three different laser processing machines with varying laser wavelengths. The visibility evaluation using the IR laser was performed for all examples and comparative examples, while the visibility evaluation using the UV laser and green laser was performed for some examples and comparative examples. The laser wavelengths and laser marking conditions for each laser processing machine are shown below: (1) Laser processing machine using an IR laser (KOSES, KLM405) ・Wavelength: 1064 nm ・Power: 11 W ・Marking speed: 250 mm / sec (2) Laser processing machine using a green laser (KOSES, KLM405) ・Wavelength: 532 nm ・Power: 6 W ・Marking speed: 250 mm / sec (3) Laser processing machine using a UV laser (KEYENCE, MD-U1000C) ・Wavelength: 355 nm ・Power: 6 W ・Marking speed: 250 mm / sec

[0067] 3.3 Adhesion Strength A frustoconical LCM material cured product with a height of 7 mm, an upper base diameter of 3 mm, and a lower base diameter of 5 mm was formed on a Si substrate that had undergone SiN passivation treatment. The cured product was formed by filling a mold placed on the Si substrate with LCM material and then heat-treating it at 150°C for 60 minutes. Subsequently, using a universal bond tester Series 4000 (Nordson Advanced Technologies), the adhesive strength was evaluated by the value of the load at which the cured product peeled off the Si substrate when the load applied to the side surface of the cured product was gradually increased. The values ​​in the table represent the adhesive strength per unit area, calculated by dividing the load by the area of ​​the LCM material cured product and multiplying by the acceleration due to gravity.

[0068] 3.4 Warpage Warpage was evaluated using the following procedure. First, the upper and lower molds of the compression molding apparatus (TOWA Corporation, CPM1080) were heated to 150°C, and an FR4 substrate (GN74240: Globalnet Corporation) measuring 74 mm in length, 240 mm in width, and 300 μm in thickness was placed in the upper mold. Next, LCM material was applied to the release film, and the release film was placed in the lower mold of the compression molding apparatus with the LCM material-coated side facing upwards. Then, the lower mold was operated, and compression molding was performed at 150°C / 300 seconds. The size of the hardened material formed on the FR4 substrate was 67 mm in length, 233 mm in width, and 250 μm in thickness. After the compression molding was completed, the FR4 substrate with the hardened material formed was removed from the mold and placed in a dryer set to 180°C for 1 hour of heat treatment. This resulted in an evaluation sample in which a layer of hardened LCM material was formed on one side of the FR4 substrate. Next, the evaluation sample was placed on a horizontal stand with the side where the hardened layer was formed facing upwards. In this state, the distance from the bottom surface of the evaluation sample to the stand was measured. Measurements were taken at all four corners of the evaluation sample, and the maximum value among these four corner measurements was taken as the value of warpage.

[0069] 3.5 Dielectric Breakdown Voltage An evaluation sample was obtained in which a layer of hardened LCM material was formed on the stainless steel plate by heat treatment of a stainless steel plate (300 μm thick) coated with LCM material on one side, placed in a dryer set to 180°C for 1 hour. The hardened material formed on the stainless steel plate measured 40 mm in length, 40 mm in width, and 150 μm in thickness. Next, the dielectric breakdown voltage was measured using a dielectric breakdown voltage tester (DAC-6041, manufactured by Soken Electric Co., Ltd.) while the evaluation sample was immersed in a fluorine-based inert liquid (Fluorinert FC-43, manufactured by 3M). For the measurement, the evaluation sample was placed on a circular electrode with a diameter of 25 mm, with the hardened material surface facing upwards. Then, a spherical electrode with a diameter of 20 mm was placed on the side of the evaluation sample opposite to the side where the circular electrode was placed. In this state, a voltage was applied to the evaluation sample at a boosting rate of 200 V / sec, and the dielectric breakdown voltage was measured.

[0070] 3.6 Viscosity The viscosity of the LCM material for each example and comparative example was measured at 25°C using a B-type viscometer (Brookfield DV-l) at a rotation speed of 20 rpm within one hour of preparation.

[0071]

[0072]

Claims

1. A liquid compression molding material comprising (A) epoxy resin, (B) curing agent, (C) inorganic filler, and (D) coloring agent, wherein the absorbance measured using a photometer under the following absorbance measurement conditions is 3.5 or higher. (Absorbance measurement conditions) - Measurement sample: Cured product obtained by heating the liquid compression molding material at 150°C for 60 minutes - Thickness of measurement sample: 260 μm - Measurement wavelength: 1064 nm 2. The liquid compression molding material according to claim 1, wherein the (D) coloring agent comprises carbon black or black titanium oxide.

3. The liquid compression molding material according to claim 1 or 2, wherein the (D) coloring agent comprises at least carbon black.

4. The liquid compression molding material according to any one of claims 1 to 3, wherein the content of the coloring agent (D) is 0.1% by mass to 5.0% by mass.

5. A liquid compression molding material comprising (A) epoxy resin, (B) a hardening agent, (C) an inorganic filler, and (D1) carbon black, wherein the content of (D1) carbon black is 0.1% by mass to 5.0% by mass.

6. The liquid compression molding material according to any one of claims 2 to 5, wherein the oil absorption amount per 100g of carbon black is 100 to 200 ml / 100g.

7. A liquid compression molding material according to any one of claims 1 to 6, further comprising a curing accelerator.

8. The liquid compression molding material according to any one of claims 1 to 7, wherein the content of the inorganic filler (C) is 55% by mass to 85% by mass.

9. A cured product of a liquid compression molding material according to any one of claims 1 to 8.

10. An electronic component comprising the cured product described in claim 9.

11. A semiconductor device comprising the cured product described in claim 9.

Images