Multi-chip module substrate

Abstract

Provided is a mounting substrate provided with: a substrate; a plurality of semiconductor chips mounted on at least one surface of the substrate; and a sealing layer covering the surface of the substrate on which the plurality of semiconductor chips are mounted, the mounting substrate being characterized in that, in the thickness direction of the mounting substrate, when the thickness of the sealing layer is T and the distance from the upper surface of each semiconductor chip mounted on the substrate to the surface of the sealing layer is tn, T: tn is 10: 1.0 to 10: 5.0; the sealing layer is formed from a cured product of a curable resin composition containing a colorant in a proportion of 0.60 to 4.0 mass%.

Description

Technical Field

[0001] The present invention relates to a mounting substrate, and more specifically, to a mounting substrate formed by sealing the surface of a substrate on which a plurality of semiconductor chips are mounted by a sealing layer. Background Technology

[0002] The sealing of chip-type assemblies such as semiconductor elements and electronic components has traditionally been achieved through methods such as transfer molding using powdered epoxy resin compositions, canning using liquid epoxy resin compositions or silicone resins, dispensing, and printing. These sealing materials typically consist of epoxy resin, curing agents, curing accelerators, inorganic fillers, and colorants. Coloring is applied to prevent electrical faults caused by photoexcitation currents generated when light shines on the chip or to suppress mold marks (e.g., Patent Document 1).

[0003] In recent years, with the increasing functionality, miniaturization, and thinning of electronic components, multi-chip modules, which integrate multiple semiconductor chips and electronic components into a single package, have been researched and put into practical use as a semiconductor packaging manufacturing technology. In such multi-chip modules and other electronic components, multiple chip components and electronic components are mounted on a common substrate and sealed using a resin composition. Furthermore, as highly integrated components are currently being manufactured, to efficiently produce surface acoustic wave (SAW) components, crystal components, and other components that require a hollow interior after sealing, it is necessary to uniformly seal and encapsulate them on a substrate containing multiple chip-type components.

[0004] In the mounting substrate described above, which achieves high functionality and low cost by loading different types of semiconductor chips and multiple electronic components, in accordance with the design, high-density areas where semiconductor chips and other electronic components are arranged in a high density and low-density areas where they are arranged in a low density are mixed on a single wiring substrate (e.g., Patent Document 2).

[0005] Existing technical documents

[0006] Patent documents

[0007] Patent Document 1: Japanese Patent Application Publication No. 2005-206621

[0008] Patent Document 2: Japanese Patent Application Publication No. 2014-183085. Summary of the Invention

[0009] Previously, there was an issue with the appearance of thin-film packaging substrates: mold marks appeared on the shape of the internal semiconductor chips after sealing. In particular, in mounting substrates with multiple semiconductor chips as described above, the size and color of each semiconductor chip and electronic component were different. Therefore, once mold marks appeared, the mounting position of the semiconductor chips and electronic components could be predicted, and the internal structure of the mounting substrate could be known simply by identifying the appearance.

[0010] Therefore, the main objective of this invention is to provide a mounting substrate that can suppress the generation of mold marks.

[0011] The inventors of this invention, focusing on the thickness of the semiconductor chip and the thickness of the sealing layer, have concluded that as long as the thickness of the semiconductor chip and the thickness of the sealing layer are within a predetermined range, and the colorant contained in the cured product of the curable resin composition constituting the sealing layer is in a predetermined mixing ratio, mold marks can be suppressed even when mounting a substrate. This invention is based on this conclusion. In other words, the key points of this invention are as follows.

[0012] [1] A mounting substrate comprising:

[0013] substrate;

[0014] Multiple semiconductor chips are mounted on at least one surface of the substrate; and

[0015] A sealing layer covers the substrate surface on which the plurality of semiconductor chips are mounted.

[0016] The feature of mounting substrate is that

[0017] In the thickness direction of the mounting substrate, the thickness of the sealing layer is defined as T, and the distance from the upper surface of each semiconductor chip mounted on the substrate to the surface of the sealing layer is defined as t. n In the case of T:t n The ratio is between 10:1.0 and 10:5.0.

[0018] The sealing layer is formed from a cured product of a curable resin composition containing a colorant in a proportion of 0.60 to 4.0% by mass.

[0019] [2] The mounting substrate as described in [1], wherein the t n It is above 50μm.

[0020] [3] The mounting substrate as described in [1] or [2], wherein T is 100 to 500 μm.

[0021] [4] The mounting substrate as described in any one of [1] to [3], wherein the curable resin composition further comprises a thermosetting resin.

[0022] [5] The mounting substrate as described in any one of [1] to [4], wherein the colorant comprises carbon black and titanium black.

[0023] [6] The mounting substrate as described in any one of [1] to [5], wherein the curable resin composition further comprises a thermoplastic resin having a glass transition temperature of less than 20°C and a weight-average molecular weight of more than 30,000.

[0024] [7] The mounting substrate as described in [5], wherein the colorant contains carbon black and titanium black in a ratio of 1:1.1 to 1:7 on a mass basis.

[0025] [8] The mounting substrate as described in any one of [1] to [6], wherein 3 to 6 of the semiconductor chips constitute a unit and the distance between adjacent units is less than 1 mm.

[0026] According to the present invention, by making the thickness of the semiconductor chip and the thickness of the sealing layer within a predetermined range, and by making the colorant contained in the cured product of the curable resin composition constituting the sealing layer in a predetermined mixing ratio, a mounting substrate capable of suppressing the generation of mold marks can be provided. Attached Figure Description

[0027] Figure 1 This is a front view of one embodiment of the present invention, namely, the mounting substrate.

[0028] Figure 2 for Figure 1 The X-X' section view of the front view.

[0029] Figure 3 This is a schematic cross-sectional view of the dry film used to form the sealing layer.

[0030] Explanation of icon symbols:

[0031] 1. Mounting substrate

[0032] 10 substrates

[0033] Units of multiple semiconductor chips, 20A and 20B

[0034] 201, 202..., 216 semiconductor chips

[0035] 30 sealing layers

[0036] 40 dry film

[0037] 401 First Membrane

[0038] 402 resin layer

[0039] 403 Second membrane. Detailed Implementation

[0040] [Mounting the substrate]

[0041] A mounting substrate comprises: a substrate; a plurality of semiconductor chips mounted on at least one surface of the substrate; and a sealing layer covering the substrate surface on which the plurality of semiconductor chips are mounted. The mounting substrate is characterized in that...

[0042] In the thickness direction of the mounting substrate, the thickness of the sealing layer is defined as T, and the distance from the upper surface of each semiconductor chip mounted on the substrate to the surface of the sealing layer is defined as t. n In the case of T:t n The ratio is between 10:1.0 and 10:5.0.

[0043] The sealing layer is formed from a cured product of a curable resin composition containing a colorant in a proportion of 0.60 to 4.0% by mass.

[0044] While referring to the appendix Figure 1 The mounting substrate according to one embodiment of the present invention will be described below. Figure 1 This is a front view of one embodiment of the present invention, namely, the mounting substrate. Figure 2 for Figure 1 The X-X' section view of the front view. The mounting substrate 1 includes: a substrate 10 and a sealing layer 30 covering the main surface of the substrate 10 on which multiple semiconductor chips 201, 202, ..., 216 are mounted. The multiple semiconductor chips 201, 202, ..., 216 are arranged in groups of 3 to 6. Figure 1 Six semiconductor chips (201, 202, ..., 216) constitute one unit 20A, 20B. Adjacent units 20A and 20B are separated by a predetermined interval. Furthermore, although not shown in the figures, in addition to the substrate 10 and semiconductor chips 201, 202, ..., 216, conductor circuits can also be patterned on the surface of the substrate 10. The sealing layer 30 is configured to have a predetermined thickness (T) covering the main surface of the substrate 10. The sealing layer 30 is configured to have distances t1, t2, t3 from the upper surface of each semiconductor chip 211, 212, 213, ... mounted on the main surface of the substrate 10 to the surface of the sealing layer 30. In this invention, when viewed in cross-section along the thickness direction of the mounting substrate 1, the substrate 10 side of the mounting substrate 1 is designated as "lower," and the sealing layer 30 side is designated as "upper."

[0045] [Substrate]

[0046] As the substrate used for mounting substrates in this invention, conventionally known substrates can be used. Examples of substrates include, in addition to printed wiring boards or flexible printed wiring boards with circuits pre-formed using copper or the like, copper-clad laminates of all grades (FR-4, etc.) made of materials such as copper-clad laminates for high-frequency circuits. Other examples include metal substrates, polyimide films, polyethylene terephthalate (PET) films, polyethylene naphthalate (PEN) films, glass substrates, ceramic substrates, and wafers (including wafers before monolithization). The copper-clad laminate for high-frequency circuits is made using phenolic paper, paper epoxy resin, glass cloth epoxy resin, glass polyimide, glass cloth / non-woven epoxy resin, glass cloth / paper epoxy resin, synthetic fiber epoxy resin, fluoropolymer / polyethylene / polyphenylene ether, polyphenylene ether / cyanate, etc.

[0047] The thickness of the substrate is not particularly limited, but is preferably 3.0 mm or less, more preferably 2.0 mm or less, even more preferably 1.0 mm or less, and preferably 0.1 mm or more, more preferably 0.2 mm or more, and even more preferably 0.5 mm or more. As long as the thickness of the substrate is within the above range, the overall thickness of the mounting substrate can be reduced while maintaining strength.

[0048] [Semiconductor Chips]

[0049] The semiconductor chip used in the mounting substrate of this invention is not particularly limited in terms of size, thickness, material, color, attachments, function, etc., and all types of conventionally known semiconductor chips can be used. Furthermore, the semiconductor chip used here includes, in addition to conventional semiconductor chips, surface acoustic wave filter elements (SAW filter elements), crystal oscillator elements, high-frequency elements, accelerometers, etc. The mounting substrate of this invention comprises a unit consisting of a plurality of (at least two) semiconductor chips. There is no particular limitation as long as the number of semiconductor chips included in a unit is at least two, and it can be 50 or less, preferably 2 or more and 10 or less. The semiconductor chips included in a unit can be different in shape or color, or several of them can have the same shape or color. The distance between adjacent units can be 1 mm or less, or 0.4 to 0.7 mm. Furthermore, the distance between adjacent semiconductor chips constituting a unit can be 0.1 to 1 mm, or 0.2 to 0.6 mm.

[0050] In addition, the semiconductor chip mounted on the substrate does not necessarily need to be designed so that there is no gap between the substrate and the semiconductor chip. For example, it can be designed to have a predetermined gap between the substrate and the semiconductor chip, just like SAW filter elements.

[0051] [Sealing layer]

[0052] The sealing layer is configured to have a predetermined thickness (T) such that it covers the main surface of the substrate. Furthermore, the sealing layer is configured to have a predetermined distance (t) between the upper surface of each semiconductor chip mounted on the substrate and the upper surface of the sealing layer. n In this invention, the thickness of the sealing layer is defined as T in the thickness direction of the mounting substrate, and the distance from the upper surface of each semiconductor chip mounted on the substrate to the surface of the sealing layer is defined as t. n In this case, adjust the thickness of the sealing layer to make T:t n The ratio is between 10:1.0 and 10:5.0. Furthermore, the thickness T of the sealing layer refers to the distance from the surface of the substrate on which the semiconductor chip is mounted to the surface of the sealing layer. As described below, a colorant is included in the cured product of the curable resin composition constituting the sealing layer at a ratio of 0.60 to 4.0% by mass. As mentioned above, the thickness of the sealing layer is adjusted so that the thickness of the semiconductor chip and the thickness of the sealing layer are in a predetermined relationship, thereby suppressing the formation of mold marks even on mounting substrates where the sizes or colors of the mounted semiconductor chips differ. T:t n The preferred range is 10:2.0 to 10:4.0.

[0053] The thickness (T) of the sealing layer is adjusted to satisfy the above relationship. However, in mounting substrates such as thin-film packaging substrates, there are cases where the thickness (T) of the sealing layer is set to 500 μm or less. The preferred thickness (T) of the sealing layer is 100 to 500 μm, and more preferably 150 to 400 μm. Furthermore, as mentioned above, the shape, etc., of each semiconductor chip can also vary. n The preferred range is 50 μm or larger.

[0054] Furthermore, as described above, when there is a gap between the semiconductor chip mounted on the substrate and the substrate, it is preferable to provide a sealing layer in a manner in which the sealing layer does not fill the gap (that is, there is no penetration of the sealing layer).

[0055] Next, the cured product of the curable resin composition constituting the sealing layer will be described. The composition of the curable resin composition used to form the sealing layer is not particularly limited, but as mentioned above, it contains a colorant in a proportion of 0.60 to 4.0% by mass. In addition to the colorant, the curable resin composition typically also contains a thermosetting resin, a curing agent, inorganic fillers, etc. The curable resin composition will be described below.

[0056] [Thermosetting resins]

[0057] As a thermosetting resin, without particular limitation, the following commonly known thermosetting resins may be used: resins having cyclic ether groups and / or cyclic thioether groups, polyisocyanate compounds, terminal isocyanate compounds, melamine resins, benzoguanamine resins and other amine resins and their derivatives, bismaleimide, oxazine, cyclic carbonate compounds, carbodiimide resins, etc. Among these resins, epoxy resins are suitable.

[0058] Epoxy resin is a resin containing epoxy groups, and conventionally known epoxy resins can be used. Examples include: difunctional epoxy resins having two epoxy groups in the molecule, and polyfunctional epoxy resins having three or more epoxy groups in the molecule. Hydrogenated epoxy resins can also be used. The curable resin composition includes at least one of a semi-solid epoxy resin and a crystalline epoxy resin as the epoxy resin. One or more semi-solid epoxy resins and crystalline epoxy resins can be used alone or in combination. Furthermore, the curable resin composition may also contain a solid epoxy resin or a liquid epoxy resin. In this specification, solid epoxy resin refers to an epoxy resin that is solid at 40°C, semi-solid epoxy resin refers to an epoxy resin that is solid at 20°C and liquid at 40°C, and liquid epoxy resin refers to an epoxy resin that is liquid at 20°C.

[0059] Examples of semi-solid epoxy resins include: bisphenol A type epoxy resins such as EPICLON 860, EPICLON 900-IM, EPICLON EXA-4816, and EPICLON EXA-4822 manufactured by D.C.; Araldite AER280 manufactured by Asahi Ciba Corporation; EPOTOHTO YD-134 manufactured by Toto Chemical Co., Ltd.; jER834 and jER872 manufactured by Mitsubishi Chemical Co., Ltd.; and ELA-134 manufactured by Sumitomo Chemical Co., Ltd.; naphthalene type epoxy resins such as EPICLON HP-4032 manufactured by D.C.; and phenolic varnish type epoxy resins such as EPICLON N-740 manufactured by D.C.

[0060] The semi-solid epoxy resin is preferably composed of at least one selected from the group consisting of bisphenol A type epoxy resin, naphthalene type epoxy resin, and phenolic varnish type epoxy resin. By including a semi-solid epoxy resin, the glass transition temperature (Tg) of the cured product is increased, the CTE is decreased, and the crack resistance is excellent.

[0061] As crystalline epoxy resins, for example, crystalline epoxy resins having biphenyl, sulfide, phenylene, or naphthalene structures can be used. Biphenyl-type epoxy resins are provided, for example, as jER YX4000, jERYX4000H, jER YL6121H, jER YL6640, and jER YL6677 manufactured by Mitsubishi Chemical Corporation; diphenyl sulfide-type epoxy resins are provided, for example, as EPOTOHTO YSLV-120TE manufactured by Toto Chemical Corporation; phenylene-type epoxy resins are provided, for example, as EPOTOHTO YDC-1312 manufactured by Toto Chemical Corporation; and naphthalene-type epoxy resins are provided, for example, as EPICLON HP-4032, EPICLON HP-4032D, and EPICLON HP-4700 manufactured by D.E. Alternatively, EPOTOHTO YSLV-90C manufactured by Toto Chemical Co., Ltd., and TEPIC-S (triglycidyl isocyanate) manufactured by Nissan Chemical Industries Co., Ltd. can also be used as crystalline epoxy resins.

[0062] Examples of solid epoxy resins include: HP-4700 (naphthalene-type epoxy resin) and EXA4700 (quadrifunctional naphthalene-type epoxy resin) manufactured by D.C., and NC-7000 (multifunctional solid epoxy resin containing a naphthalene skeleton) manufactured by Nippon Kayaku Co., Ltd.; epoxides (triphenol-type epoxy resins) consisting of condensates of phenols and aromatic aldehydes with phenolic hydroxyl groups, such as EPPN-502H (triphenol epoxy resin) manufactured by Nippon Kayaku Co., Ltd.; and EPICLON manufactured by D.C. HP-7200H (a multifunctional solid epoxy resin containing a dicyclopentadiene backbone) and other dicyclopentadiene aralkyl type epoxy resins; NC-3000H (a multifunctional solid epoxy resin containing a biphenyl backbone) manufactured by Nippon Kayaku Co., Ltd. and other biphenyl aralkyl type epoxy resins; NC-3000L, a biphenyl / phenol varnish type epoxy resin manufactured by Nippon Kayaku Co., Ltd.; EPICLON N660, EPICLON N690, N770, and EOCN-104S, phenolic varnish type epoxy resins manufactured by D.E.S. Ltd.; TX0712, a phosphorus-containing epoxy resin manufactured by Nippon Steel & Sumitomo Chemical Co., Ltd.; and tris(2,3-epoxypropyl) isocyanurate such as TEPIC, manufactured by Nissan Chemical Industries Co., Ltd. By incorporating solid epoxy resins, the glass transition temperature of the cured product is increased, resulting in excellent heat resistance.

[0063] Examples of liquid epoxy resins include: bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol AF type epoxy resin, phenolic varnish type epoxy resin, tert-butylcatechol type epoxy resin, glycidylamine type epoxy resin, aminophenol type epoxy resin, and alicyclic epoxy resin. By incorporating liquid epoxy resin, the dry film exhibits excellent flexibility.

[0064] The total amount of semi-solid epoxy resin and crystalline epoxy resin is preferably 5 to 40% by mass, more preferably 10 to 30% by mass, based on the total amount of epoxy resin. If it is within the above range, the adhesion and flexibility of the cured resin composition when it is made into a dry film are excellent.

[0065] In addition to epoxy resins, thermoplastic resins may also include isocyanate compounds, terminated isocyanate compounds, amino resins, benzoxazine resins, carbodiimide resins, cyclic carbonate compounds, polyfunctional oxobutane compounds, cyclic sulfur resins, and other commonly known thermosetting resins.

[0066] [Curing agent]

[0067] When using the thermosetting resin as described above, the curing resin composition preferably contains a curing agent. Examples of curing agents include: compounds having phenolic hydroxyl groups, polycarboxylic acids and their anhydrides, compounds having cyanate ester groups, compounds having active ester groups, compounds having maleimide groups, alicyclic olefin polymers, etc. One or more curing agents may be used alone or in combination.

[0068] The curable resin composition is preferably composed of at least one of a compound having phenolic hydroxyl groups, a compound having active ester groups, a compound having cyanate ester groups, and a compound having maleimide. By using compounds having phenolic hydroxyl groups and compounds having active ester groups, cured products with excellent adhesion to low-roughness substrates or circuits can be obtained. In addition, by using cyanate esters, the Tg of the cured product increases, and the heat resistance is improved; by using compounds having maleimide, the Tg of the cured product increases, the heat resistance is improved, and the CTE can be reduced.

[0069] As the compound having phenolic hydroxyl groups, conventionally known resins such as phenolic varnish resin, alkylphenolic varnish resin, bisphenol A varnish resin, dicyclopentadiene-type phenolic resin, Xylok-type phenolic resin, terpene-modified phenolic resin, cresol / naphthol resin, polyethylene phenol, phenol / naphthol resin, phenolic resin containing an α-naphthol skeleton, cresol varnish resin containing a triazine skeleton, biphenyl aryl alkyl-type phenolic resin, and phenol aryl alkyl-type phenolic varnish resin may be used.

[0070] Among compounds containing phenolic hydroxyl groups, the hydroxyl equivalent is preferably 100 g / eq. or more. Examples of compounds containing phenolic hydroxyl groups with a hydroxyl equivalent of 100 g / eq. or more include: dicyclopentadiene skeleton phenolic varnish resin (GDP series, manufactured by Gunei Chemical Co., Ltd.), phenol aralkyl type phenolic varnish resin (MEH-7800, manufactured by Meiwa Chemical Co., Ltd.), biphenyl aralkyl type phenolic varnish resin (MEH-7851, manufactured by Meiwa Chemical Co., Ltd.), naphthol aralkyl type curing agent (SN series, manufactured by Nippon Steel & Sumitomo Metal Corporation), cresol phenolic varnish resin containing a triazine skeleton (LA-3018-50P, manufactured by D.E.), and phenolic varnish resin containing a triazine skeleton (LA-705N, manufactured by D.E.), etc.

[0071] Among compounds containing phenolic hydroxyl groups, the hydroxyl equivalent is preferably 100 g / eq. or more. Examples of compounds containing phenolic hydroxyl groups with a hydroxyl equivalent of 100 g / eq. or more include: dicyclopentadiene skeleton phenolic varnish resin (GDP series, manufactured by Gunei Chemical Co., Ltd.), phenol aralkyl type phenolic varnish resin (MEH-7800, manufactured by Meiwa Chemical Co., Ltd.), biphenyl aralkyl type phenolic varnish resin (MEH-7851, manufactured by Meiwa Chemical Co., Ltd.), naphthol aralkyl type curing agent (SN series, manufactured by Nippon Steel & Sumitomo Metal Corporation), cresol phenolic varnish resin containing a triazine skeleton (LA-3018-50P, manufactured by D.E.), and phenolic varnish resin containing a triazine skeleton (LA-705N, manufactured by D.E.), etc.

[0072] Examples of commercially available compounds containing cyanate groups include: phenolic varnish-type multifunctional cyanate resins (manufactured by Lonza Japan, PT30S), prepolymers of bisphenol A dicyanate that have been partially or wholly triazinized to form trimers (manufactured by Lonza Japan, BA230S75), and cyanate resins containing dicyclopentadiene structures (manufactured by Lonza Japan, DT-4000, DT-7000), etc.

[0073] The compound having an active ester group is preferably a compound having two or more active ester groups per molecule. Compounds having an active ester group are generally obtained by the condensation reaction of a carboxylic acid compound and a hydroxyl compound. Among these, compounds having an active ester group obtained by using a phenolic compound or a naphthol compound as the hydroxyl compound are preferred. Examples of phenolic compounds or naphthol compounds include: hydroquinone, resorcinol, bisphenol A, bisphenol F, bisphenol S, acid phenolphthalein, methylated bisphenol A, methylated bisphenol F, methylated bisphenol S, phenol, o-cresol, m-cresol, p-cresol, catechol, α-naphthol, β-naphthol, 1,5-dihydroxynaphthol, 1,6-dihydroxynaphthol, 2,6-dihydroxynaphthol, dihydroxybenzophenone, trihydroxybenzophenone, tetrahydroxybenzophenone, gambogeylic acid, benzoglycerol, dicyclopentadienyldiol, phenolic varnish, etc. Additionally, compounds having an active ester group may also be of the naphthalene glycol alkyl / benzoic acid type.

[0074] Examples of commercially available compounds with active ester groups include dicyclopentadiene-type diphenol compounds, such as HPC8000-65T (manufactured by D.E.), HPC8100-65T (manufactured by D.E.), and HPC8150-65T (manufactured by D.E.).

[0075] Compounds containing maleimide are compounds with a maleimide skeleton, and conventionally known compounds are acceptable. Preferably, the compound contains two or more maleimide skeletons, and more preferably N,N'-1,3-phenylene dimaleimide, N,N'-1,4-phenylene dimaleimide, N,N'-4,4-diphenylmethane bismaleimide, 1,2-bis(maleimide)ethane, 1,6-bismaleimide hexane, 1,6-bismaleimide-(2,2,4-trimethyl)hexane, 2,2'-bis-[ [4-(4-maleimidephenoxy)phenyl]propane, 3,3'-dimethyl-5,5'-diethyl-4,4'-diphenylmethane bismaleimide, 4-methyl-1,3-phenylene bismaleimide, bis(3-ethyl-5-methyl-4-maleimidephenyl)methane, bisphenol A diphenyl ether bismaleimide, polyphenylmethane maleimide and oligomers thereof, and diamine condensates having a maleimide backbone, at least one of these. The oligomer is obtained by condensing a maleimide-containing compound with a monomer from the above-mentioned compounds having a maleimide backbone.

[0076] Examples of commercially available compounds containing maleimide include: BMI-1000 (4,4'-diphenylmethane bismaleimide, manufactured by Yamato Chemical Industries, Ltd.), BMI-2300 (phenylmethane bismaleimide, manufactured by Yamato Chemical Industries, Ltd.), BMI-3000 (m-phenylene bismaleimide, manufactured by Yamato Chemical Industries, Ltd.), BMI-5100 (3,3'-dimethyl-5,5'-dimethyl-4,4'-diphenylmethane bismaleimide, manufactured by Yamato Chemical Industries, Ltd.), BMI-7000 (4-methyl-1,3'-phenylene bismaleimide, manufactured by Yamato Chemical Industries, Ltd.), and BMI-TMH ((1,6-bismaleimide-2,2,4-trimethyl)hexane, manufactured by Yamato Chemical Industries, Ltd.).

[0077] The amount of curing agent incorporated is preferably 20 to 100 parts by weight relative to 100 parts by weight of the thermosetting resin, and more preferably 25 to 90 parts by weight.

[0078] [Curing Accelerator]

[0079] Curable resin compositions may contain curing accelerators used in conjunction with curing agents. Curing accelerators are components that promote thermosetting reactions and are used to further improve properties such as adhesion, chemical resistance, and heat resistance. Specific examples of such curing accelerators include: imidazoles and their derivatives; guanidines such as ethylguanidine and phenylguanidine; polyamines such as diamine diphenylmethane, m-phenylenediamine, m-phenylenediamine, diaminodiphenyl sulfone, dicyandiamide, urea, urea derivatives, melamine, and polyhydrazides; their organic acid salts and / or epoxy adducts; amine complexes of boron trifluoride; triazine derivatives such as ethyldiamino-symmetric triazine, 2,4-diamino-symmetric triazine, and 2,4-diamino-6-dimethyl-symmetric triazine; trimethylamine, triethanolamine, N,N-dimethyloctylamine, N-benzyldimethylamine, pyridine, and N-methyl Amines such as porphyrin, hexa(N-methyl)melamine, 2,4,6-tris(dimethylaminophenol), tetramethylguanidine, and m-aminephenol; polyphenols such as polyvinylphenol, brominated polyvinylphenol, phenolic varnish, and alkylphenolic varnish; organophosphorus compounds such as tributylphosphine, triphenylphosphine, and tris(2-cyanoethylphosphine); phosphonium salts such as tri-n-butyl(2,5-dihydroxyphenyl)phosphine bromide and hexadecyltributylphosphine chloride; and benzyltrimethylammonium chloride and phenyltributylphosphine chloride. The curing accelerators include quaternary ammonium salts such as ammonium; polyacid anhydrides; photocationic polymerization catalysts such as diphenyliodonium tetrafluoroborate, triphenylsulfonium hexafluoroantimonate, and 2,4,6-triphenylpyranium hexafluorophosphate; styrene-maleic anhydride resin; equimolar reactants of phenyl isocyanate and dimethylamine, and equimolar reactants of organic polyisocyanates such as methylphenylene diisocyanate and isophorone diisocyanate with dimethylamine; and metal catalysts. Among the curing accelerators, phosphonium salts are preferred from the viewpoint of achieving high accelerated stress resistance under bias voltage.

[0080] Curing accelerators can be used alone or in combination of two or more. While the use of a curing accelerator is not mandatory, it is particularly desirable to use 0.01 to 5 parts by weight relative to 100 parts by weight of epoxy resin, especially when accelerated curing is desired. In the case of a metal catalyst, the metal conversion is preferably 10 to 550 ppm, more preferably 25 to 200 ppm, relative to 100 parts by weight of the compound having a cyanate group.

[0081] [Coloring agent]

[0082] In the curable resin composition used to form a sealing layer, a colorant is included in a proportion of 0.60 to 4.0% by mass (based on solids content). If the proportion of the colorant is 0.60% by mass or more, mold marks can be suppressed by adjusting the thickness of the sealing layer. Furthermore, if the proportion of the colorant is less than 4.0% by mass, the dispersibility of the curable resin composition can be improved. A preferred proportion of the colorant is 0.60 to 2.5% by mass.

[0083] As a colorant, known colorants used in conventional sealing materials can be used, such as phthalocyanine blue, phthalocyanine green, iodine green, diazo yellow, crystal violet, carbon black, titanium black, and naphthalene black. Among these, carbon black and titanium black are suitable from the viewpoint of suppressing mold marks.

[0084] In this invention, it is preferred to use carbon black and titanium black together as colorants. When both are used together, it is further preferred to include carbon black and titanium black in a ratio of 1:1.1 to 1:7 by weight, and even more preferably in a ratio of 1:2 to 1:4.

[0085] [Other resin components]

[0086] To improve mechanical strength, the curable resin composition used to form the sealing layer may further contain a thermoplastic resin. The thermoplastic resin is preferably soluble in a solvent. Solvent soluble resins improve the flexibility of the dry film, thereby suppressing crack formation or powdering. Examples of thermoplastic resins include: thermoplastic polyhydroxyl polyether resins, phenoxy resins of epichlorohydrin condensates with various difunctional phenolic compounds, or phenoxy resins formed by esterifying the hydroxyl groups present in the hydroxyl ether portion of their backbone using various acid anhydrides or acyl chlorides, polyvinyl acetal resins, polyamide resins, polyamide-imide resins, block copolymers, etc. One or more thermoplastic resins may be used alone or in combination.

[0087] The curable resin composition may also include, for example, a thermoplastic resin with a glass transition temperature of 20°C or lower and a weight-average molecular weight of 30,000 or higher. Since a higher weight-average molecular weight of the polymer resin results in a greater effect on preventing sedimentation of the inorganic filler, a weight-average molecular weight of 100,000 or higher is preferred, and more preferably 200,000 or higher. An upper limit, for example, is 1,000,000 or lower.

[0088] Examples of thermoplastic resins include polymeric resins having one or more skeletons selected from butadiene skeletons, amide skeletons, imide skeletons, acetal skeletons, carbonate skeletons, ester skeletons, carbamate skeletons, acrylic skeletons, and siloxane skeletons. Examples include: polymer resins with a butadiene backbone (such as "G-1000", "G-3000", "GI-1000", "GI-3000" manufactured by Nippon Soda Co., Ltd., "R-45EPI" manufactured by Idemitsu Petrochemical Co., Ltd., "PB3600" and "Epofriend AT501" manufactured by Daicel Chemical Industry Co., Ltd., and "Ricon130", "Ricon142", "Ricon150", "Ricon657", and "Ricon130MA" manufactured by Clayville Co., Ltd.); polymer resins with both a butadiene backbone and a polyimide backbone (such as the resin described in Japanese Patent Application Publication No. 2006-37083); and polymer resins with an acrylic backbone (such as "SG-P3", "SG-600LB", "SG-280", "SG-790", "SG-K2" manufactured by Nagase ChemteX Co., Ltd., and "SN-50", "AS-3000E", and "ME-2000" manufactured by Negami Kogyo Co., Ltd.).

[0089] From the viewpoint of the flatness of the cured product, acrylic copolymers with a glass transition temperature of 20°C or lower and a weight-average molecular weight of 200,000 or higher are preferred as thermoplastic resins. Furthermore, from the viewpoint of adhesion to biaxially extended polypropylene (OPP) films and adhesion to low-roughness substrates or circuits, acrylic copolymers with a glass transition temperature of -5 to 15°C and a weight-average molecular weight of 200,000 to 500,000 are preferred.

[0090] Acrylic copolymers may also have functional groups, such as carboxyl, hydroxyl, epoxy, and amide groups. Preferably, the acrylate copolymer has epoxy groups, and more preferably, it has both epoxy and amide groups. The presence of epoxy groups helps to suppress warping of the cured product.

[0091] Examples of acrylate copolymers include TEISANRESIN SG-70L, SG-708-6, WS-023EK30, SG-P3, SG-80H, SG-280EK23, SG-600TEA, and SG-790 manufactured by Nagase ChemteX Co., Ltd. These acrylate copolymers can also be synthesized; for example, the synthesis method described in Japanese Patent Application Publication No. 2016-102200 can be cited as a synthesis method.

[0092] The thermoplastic resin can be used alone or in combination of two or more. Based on the total solids content of the composition, the amount of the polymer incorporated is preferably 0.5 to 10% by mass, more preferably 1.0 to 7.0% by mass, even more preferably 2.0 to 7.0% by mass, and still even more preferably 4.0 to 7.0% by mass.

[0093] Based on the total solid content of the curable resin composition, the amount of thermoplastic resin incorporated is preferably 0.5 to 20% by mass, more preferably 0.5 to 10% by mass. If the amount of thermoplastic resin incorporated is within the above range, a uniform roughened surface state can be easily obtained, which results in the suppression of mold marks.

[0094] Rubber-like particles can be included in the curable resin composition as needed. Examples of such rubber-like particles include: polybutadiene rubber, polyisopropylene rubber, urethane-modified polybutadiene rubber, epoxy-modified polybutadiene rubber, acrylonitrile-modified polybutadiene rubber, carboxyl-modified polybutadiene rubber, acrylonitrile-butadiene rubber modified with carboxyl or hydroxyl groups, and their cross-linked rubber particles, core-shell rubber particles, etc., which can be used alone or in combination of two or more. These rubber-like particles are added to improve the flexibility of the obtained cured film, improve crack resistance, make it possible to roughen the surface with an oxidizing agent, and improve the adhesion strength to copper foil, etc.

[0095] The average particle size of the rubber-like particles is preferably in the range of 0.005 to 1 μm, and more preferably in the range of 0.2 to 1 μm. The average particle size of the rubber-like particles in this invention can be determined using a laser diffraction particle size distribution measuring device. For example, it can be determined by uniformly dispersing the rubber-like particles in a suitable organic solvent using ultrasound or the like, and using a Nanotrac wave manufactured by Nikkiso Corporation to prepare the particle size distribution of the rubber-like particles based on mass, and taking its median diameter as the average particle size.

[0096] Based on the total solids content of the curable resin composition, the amount of rubber-like particles incorporated is preferably 0.5 to 10% by mass, more preferably 1 to 5% by mass. At 0.5% by mass or more, crack resistance is obtained, and adhesion strength to conductor patterns, etc., is improved. At 10% by mass or less, the coefficient of thermal expansion (CTE) decreases, the glass transition temperature increases, and curing properties are improved.

[0097] [Inorganic filler materials]

[0098] Inorganic fillers can also be included in the curable resin composition as needed. By incorporating inorganic fillers, the curing shrinkage of the resulting cured product can be suppressed, and thermal properties such as adhesion, hardness, and crack resistance due to the conductive layer such as copper surrounding the insulating layer can be improved. Conventionally known inorganic fillers can be used as inorganic fillers, and while not limited, examples include: barium sulfate, barium titanate, amorphous silica, crystalline silica, fused silica, spherical silica, talc, clay, Noieburg silica particles, gibbsite, magnesium carbonate, calcium carbonate, titanium dioxide, aluminum oxide, aluminum hydroxide, silicon nitride, aluminum nitride, calcium zirconate, and other extender pigments; and metal powders such as copper, tin, zinc, nickel, silver, palladium, aluminum, iron, cobalt, gold, and platinum. Spherical particles are preferred as the inorganic filler. Silica is particularly preferred, as it suppresses the curing shrinkage of the cured product of the curable composition, resulting in a lower CTE, and also improves properties such as adhesion and hardness. Furthermore, inorganic filler materials with a relatively high specific gravity, such as alumina, generally have a faster settling rate, but settling can be suppressed in this invention, making them suitable for use. The average particle size (median diameter, D50) of the inorganic filler material is preferably 0.01 to 10 μm. From the viewpoint of slit processability, silica with an average particle size of 0.01 to 3 μm is preferred as the inorganic filler material. In this specification, the average particle size of the inorganic filler material includes both the particle size of primary particles and the particle size of secondary particles (aggregates). The average particle size can be determined using a laser diffraction-based particle size distribution measuring device. Examples of measuring devices utilizing laser diffraction include the Nanotra Wave manufactured by Nikkiso Corporation.

[0099] Inorganic filler materials can also undergo surface treatment. As a surface treatment, non-organic-based surface treatments such as those using coupling agents or alumina treatment can be performed. There are no particular limitations on the surface treatment method for inorganic filler materials; any known and commonly used method is acceptable. The surface of the inorganic filler material can be treated with a surface treatment agent having curable reactive groups, such as a coupling agent with curable reactive groups as an organic group.

[0100] The surface treatment of inorganic filler materials is preferably performed using a coupling agent. As coupling agents, silane-based, titanate-based, aluminate-based, and aluminozirconate-based coupling agents can be used. Silane-based coupling agents are preferred. Examples of such silane-based coupling agents include: vinyltrimethoxysilane, vinyltriethoxysilane, N-(2-aminomethyl)-3-aminopropylmethyldimethoxysilane, N-(2-aminoethyl)-3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 3-phenylaminopropyltrimethoxysilane, 3-epoxypropoxypropyltrimethoxysilane, 3-epoxypropoxypropylmethyldimethoxysilane, 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, 3-methacryloyloxypropyltrimethoxysilane, 3-mercaptopropyltrimethoxysilane, etc., which can be used alone or in combination. These silane-based coupling agents are preferably pre-immobilized on the surface of the inorganic filler material by adsorption or reaction. Here, the amount of coupling agent treated is, for example, 0.5 to 10 parts by mass relative to 100 parts by mass of the inorganic filler material.

[0101] As a curable reactive group, a thermosetting reactive group is preferred. Examples of thermosetting reactive groups include: hydroxyl, carboxyl, isocyanate, amino, imino, epoxy, oxetyl, mercapto, methoxymethyl, methoxyethyl, ethoxymethyl, ethoxyethyl, oxazoline, etc. Among them, at least one of amino and epoxy groups is preferred. In addition, surface-treated inorganic filler materials may also have photocurable reactive groups in addition to thermosetting reactive groups.

[0102] Furthermore, the surface-treated inorganic filler can be included in the curable resin composition in a surface-treated state. Alternatively, the inorganic filler and the surface treatment agent can be separately blended into the curable resin composition forming the sealing layer, and the inorganic filler can be surface-treated in the composition. However, it is preferable to blend in a pre-surface-treated inorganic filler. By blending in a pre-surface-treated inorganic filler, the reduction in crack resistance and other properties caused by unused surface treatment agent that may remain during surface treatment when blending separately can be prevented. In the case of pre-surface treatment, it is preferable to blend a pre-dispersion containing the inorganic filler into a solvent or curable resin. More preferably, the surface-treated inorganic filler is pre-dispersed in a solvent and then the pre-dispersion is blended into the composition, or the pre-dispersion is fully surface-treated when the untreated inorganic filler is pre-dispersed in a solvent and then blended into the composition.

[0103] Inorganic fillers can be blended with epoxy resins in powder or solid form, or they can be blended with epoxy resins after being mixed with solvents or dispersants to form a slurry.

[0104] The inorganic filler material can be used alone or as a mixture of two or more. Based on the total solid content of the curable resin composition, the amount of inorganic filler material is preferably 10 to 90% by mass, more preferably 50 to 90% by mass, and even more preferably 60 to 90% by mass. When the amount of inorganic filler material is 10% by mass or more, thermal expansion is suppressed and heat resistance is improved; on the other hand, when it is 90% by mass or less, crack formation can be suppressed.

[0105] The adhesion of the protective film and the sedimentation of the inorganic filler are particularly noticeable when the content of the inorganic filler is high. In this invention, when the amount of inorganic filler is relatively large, for example, when it is 50% by mass or more based on the total solids content of the curable resin composition, particularly excellent results can be obtained. Furthermore, when it is 70% by mass or more, the sedimentation of the inorganic filler is particularly noticeable, but according to this invention, the sedimentation suppression of the inorganic filler is excellent.

[0106] [Organic solvents]

[0107] The aforementioned curable resin composition may also contain organic solvents. As described below, when forming a dry film, the viscosity of the curable resin composition can be adjusted to an appropriate range to improve coatability. No particular limitations are placed on the organic solvents used; examples include ketones, aromatic hydrocarbons, glycol ethers, glycol ether acetates, esters, alcohols, aliphatic hydrocarbons, and petroleum-based solvents. Specifically, in addition to ketones such as methyl ethyl ketone, cyclohexanone, methyl butyl ketone, and methyl isobutyl ketone; aromatic hydrocarbons such as toluene, xylene, and tetramethylbenzene; glycol ethers such as celux ether, methyl celux ether, butyl celux ether, carbitol, methyl carbitol, butyl carbitol, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, propylene glycol monomethyl ether, dipropylene glycol monomethyl ether, dipropylene glycol diethyl ether, and triethylene glycol monoethyl ether; ethyl acetate, butyl acetate, isobutyl acetate, and ethylene glycol monoethyl ether... Esters such as ethanol monoethyl ether acetate, dipropylene glycol methyl ether acetate, propylene glycol methyl ether acetate, propylene glycol ethyl ether acetate, and propylene glycol butyl ether acetate; alcohols such as ethanol, propanol, 2-methoxypropanol, n-butanol, isobutanol, isoamyl alcohol, ethylene glycol, and propylene glycol; aliphatic hydrocarbons such as octane and decane; and petroleum-based solvents such as petroleum ether, naphtha, hydrogenated naphtha, and solvent naphtha, as well as N,N-dimethylformamide (DMF), tetrachloroethylene, and rosin oil, can also be listed. Alternatively, organic solvents such as Swasol 1000 and Swasol 1500 manufactured by Maruzen Petrochemical Co., Ltd., SOLVESSO 100 and SOLVESSO 150 manufactured by Standard Oil Osaka Distribution Co., Ltd., Solvent #100 and Solvent #150 manufactured by Sankyo Chemical Co., Ltd., Shellsol A100 and Shellsol A150 manufactured by Shell Chemicals Japan Co., Ltd., and Ipzole 100 and Ipzole 150 manufactured by Idemitsu Kosan Co., Ltd. can also be used. A single organic solvent can be used, or a mixture of two or more can be used.

[0108] The residual solvent content in the curable resin composition is preferably 0.5 to 7.0% by mass. If the residual solvent is less than 7.0% by mass, it suppresses boil-up during thermosetting, resulting in better surface flatness. Additionally, it suppresses resin flow caused by excessively low melt viscosity, leading to better flatness. If the residual solvent is 0.5% by mass or more, it improves flowability during lamination, and enhances both flatness and embedding properties.

[0109] [Other ingredients]

[0110] Further, as needed, conventionally known thickeners such as asbestos, ORBEN, BENTON, and microcrystalline silica can be used in the curable resin composition; defoamers and / or leveling agents such as silicone, fluorine, and polymeric agents; adhesive agents such as thiazole, triazole, and silane coupling agents; flame retardants; and conventionally known additives such as titanate and aluminum esters.

[0111] [Dry film]

[0112] The sealing layer is preferably formed using a dry film having a resin layer formed from a curable resin composition. Figure 3 This is a schematic cross-sectional view of a dry film used to form a sealing layer. The dry film 40 includes: a first film 401, a resin layer 402 disposed on one side of the first film, and a second film 403 disposed in the resin layer 402 on the side opposite to the first film 401, in contact with the resin layer 402. An intermediate layer (not shown) may also be provided between the first film 401 and the resin layer 402. When using the dry film 40, the second film 403 is peeled off to expose the resin layer 402, and the surface of the resin layer 402 of the dry film 40 is pressed onto the main surface of a substrate on which a semiconductor chip or the like is mounted. In other words, the second film 403 is provided to prevent dust or the like from adhering to the surface of the resin layer 402 and to consider the operability of the dry film 40, and is intended to be peeled off when using the dry film 40.

[0113] The first film refers to a film that is at least adhered to the resin layer when integrally formed by lamination, in which a resin layer formed from the aforementioned curable resin composition formed on a dry film is attached to a substrate such as a substrate by means of heat or the like. The first film may also be peeled off from the resin layer in a step after lamination.

[0114] As the first membrane, any known material can be used without particular limitation. For example, membranes formed from polyester films such as polyethylene terephthalate and polyethylene naphthalate, polyimide films, polyamide-imide films, polypropylene films, and polystyrene films are suitable. Among these, polyester films are preferred from the viewpoints of heat resistance, mechanical strength, and operability. Alternatively, laminates of these films can also be used as the first membrane.

[0115] Demolding treatment can also be performed on the surface of the first film where the resin layer is located. For example, by known means such as roller coating, spray coating, gravure printing, screen printing, etc., a coating liquid prepared by dissolving or dispersing release agents such as waxes, polysiloxane waxes, and polysiloxane resins in a suitable solvent can be applied to the surface of the first film and then dried to perform demolding treatment.

[0116] The thickness of the first membrane is not particularly limited; for example, it can be set from 10 μm to 150 μm.

[0117] The resin layer disposed on one side of the first film is formed from the above-described curable resin composition. The curable resin composition can be applied to the surface of the first film using a coating apparatus such as a notched roller coating apparatus, a doctor blade coating apparatus, a lip extrusion coating apparatus, a bar coating apparatus, an extrusion coating apparatus, a reverse coating apparatus, a transfer roller coating apparatus, a gravure coating apparatus, or a spray coating apparatus to achieve a uniform thickness. The resin layer is typically formed by drying at a temperature of 50 to 130°C for 1 to 30 minutes. The coating thickness is not particularly limited, but the dried film thickness is appropriately selected within the range of 5 to 40 μm, preferably within the range of 10 to 35 μm.

[0118] As a second membrane, for example, polyester film, polyethylene film, polytetrafluoroethylene film, polypropylene film, surface-treated paper, etc. can be used, but among them, polypropylene film is preferred.

[0119] Preferably, the material selected is one in which the adhesion between the second film and the resin layer is less than that between the first film and the resin layer. Additionally, to facilitate the peeling of the second film when using the dry film, the surface of the second film in contact with the resin layer may be subjected to the demolding treatment described above.

[0120] The thickness of the second membrane is not particularly limited, but can be appropriately selected in the range of approximately 10 to 60 μm depending on the application.

[0121] [Manufacturing method of mounting substrate]

[0122] Will as Figure 3 The second film 403 of the dry film 40 shown is peeled off, exposing the resin layer 402. Using a vacuum laminator or similar device, the resin layer 402 is laminated onto the main surface of a substrate on which multiple semiconductor chips are mounted, under pressure and heat. By using a vacuum laminator, the resin layer 402 adheres to the substrate, thus preventing air bubbles from being trapped even if recesses exist between the semiconductor chips mounted on the substrate surface, and forming a smooth sealing layer. The pressure conditions are preferably around 0.1 to 2.0 MPa, and the heating conditions are preferably 40 to 120°C.

[0123] After the resin layer 402 has cured, the sealing layer 30 can be formed by peeling off the first film 401. The curing of the resin layer 402 is preferably performed by hot pressing. Hot pressing can be performed using known methods such as vacuum laminators or vacuum pressing. Preferably, the temperature during hot pressing is 60 to 130°C, and the pressure is 20 kg / cm². 2 The forming time is then within 180 seconds. Next, the sealing layer 30 is heat-cured and sealed. Heat curing is performed at 100 to 200°C for approximately 30 to 180 minutes.

[0124] Example

[0125] The invention will then be further described in detail with reference to specific embodiments, but the invention is not limited to these embodiments. Furthermore, unless otherwise specified, all references to "parts" and "%" below refer to mass.

[0126] <Preparation of Curable Resin Compositions>

[0127] According to the composition shown in Table 1 below, the components are mixed and stirred, and then kneaded using a three-roll mill to prepare two curable resin compositions, A and B. Furthermore, the values ​​in the table represent parts by mass, and the contents other than solvents represent the solid content.

[0128] [Table 1]

[0129]

[0130] In addition, *1 to *11 in Table 1 represent the following components.

[0131] *1: Bisphenol A type epoxy resin (manufactured by Mitsubishi Chemical Corporation)

[0132] *2: Phenolic varnish-type epoxy resin (manufactured by D.E. Co., Ltd.)

[0133] *3: Phenolic varnish-type epoxy resin (manufactured by D.E. Co., Ltd.)

[0134] *4: Phenolic resin for varnish (manufactured by Ube Industries, Ltd.)

[0135] *5: Leveling agent (manufactured by BYK Chemical Co., Ltd., Japan)

[0136] *6: Silane coupling agent (manufactured by Shin-Etsu Silicon Co., Ltd.)

[0137] *7: Spherical silica (manufactured by Yatoma Corporation)

[0138] *8: Acrylic ester copolymer (functional group: epoxy group, Tg=12℃, Mw=850000, manufactured by Nagase ChemteX Co., Ltd.)

[0139] *9: Imidazole-based epoxy curing agent (manufactured by Shikoku Kasei Corporation)

[0140] *10: Titanium black (manufactured by Akaho Chemicals Co., Ltd.)

[0141] *11: Carbon Black (manufactured by RESINO COLOR Co., Ltd.)

[0142] *12: Cyclohexanone (manufactured by Daishin Chemical Co., Ltd.)

[0143] <Dry Film Preparation>

[0144] The amount of solvent was adjusted to achieve a viscosity of 0.5 to 20 dPa·s (rotational viscometer 5 rpm, 25°C) for the prepared curable resin composition A. Using a rod coating apparatus, the solvent was applied to a release PET film (TN201 manufactured by Toyobo Co., Ltd., 50 μm thick, 30cm × 30cm) to form a resin layer with a thickness of 200 μm after drying. Next, the film was dried in a hot air circulating drying oven at 90°C for 15 minutes to form a resin layer on the release PET film. Then, an eye-reducing OPP film (ALPHAN FG-201 manufactured by Oji F-Tex Co., Ltd.) was bonded to the surface of the formed resin layer using a roller laminator, thereby producing a dry film 1 with a resin layer thickness of 200 μm.

[0145] In addition, the coating amount of the curable resin composition A is adjusted so that the thickness of the dried resin layer is 150 μm. Otherwise, a dry film 2 with a resin layer thickness of 150 μm is prepared in the same manner as described above.

[0146] In addition, the coating amount of the curable resin composition A is adjusted so that the thickness of the dried resin layer is 240 μm. Otherwise, a dry film 3 with a resin layer thickness of 240 μm is prepared in the same manner as described above.

[0147] In addition, the curable resin composition A is changed to the curable resin composition B, and otherwise a dry film 4 with a resin layer thickness of 200 μm is prepared in the same manner as the dry film 1.

[0148] In addition, two dry films 4 are made, and the OPP film and the carrier film are peeled off from the dry films respectively. Using a roller laminator, the two resin layers are laminated at 80°C to make a dry film 5 with a resin layer thickness of 400μm.

[0149] [Example 1]

[0150] Three types of chips with thicknesses of 190μm, 200μm, and 220μm were mounted on a substrate with a gap of 10 to 15μm between them and the substrate at a spacing of 0.5mm. On an FR-4 substrate with a thickness of 0.4mm and a cured film of solder resist ink (manufactured by Taiyo Ink Co., Ltd., PSR-4000AUS308) with a thickness of 0.2mm, the resin layer was exposed by removing the OPP film with a fisheye reduction technique to form a dry film 1. The resin layer was then laminated to the FR-4 substrate in a vacuum laminator at a temperature of 55°C, a pressure of 0.5MPa, and a time of 60 seconds.

[0151] Next, the resin layer is cured by heating at 100°C for 30 minutes in a hot air circulating drying oven, followed by heating at 180°C for 30 minutes. Then, the demolded PET film is peeled off to obtain the mounting substrate.

[0152] The obtained mounting substrate was cut using an ultrasonic cutter. The cut surface was observed and the length was measured using a field emission scanning electron microscope (FE-SEM) at a magnification of 100 to 1000 times to confirm the thickness from the substrate to the resin layer and the thickness from the top of each chip.

[0153] <Inhibition effect on the occurrence of mold marks>

[0154] The surface of the sealing layer is visually inspected, and the effect of inhibiting mold marks is confirmed by the following evaluation criteria.

[0155] ◎: No mold marks are visible at all (it is impossible to discern what is inside the sealant layer even by viewing its surface).

[0156] ○: The mold marks are faintly visible (the presence of an object inside the sealing layer can be identified by observing the surface of the sealing layer).

[0157] ×: Mold marks are clearly visible (the number of mold marks can be determined by observing the surface of the sealing layer).

[0158] The evaluation results are shown in Table 2 below.

[0159] <Drilling into the sealing layer>

[0160] The obtained mounting substrate was cut using an ultrasonic cutter. After the slices were sealed with resin, they were polished using an ion polishing device to expose the cut surfaces of the slices. At this time, polishing was performed so that the substrate cross-section was approximately located in the center of the chip. Next, the exposed surface of the polished slices was observed and the length was measured using FE-SEM at a magnification of 100 to 1000, and the thickness of the sealant layer between the substrate and the chip was measured (that is, the amount of resin layer of the dry film penetrated between the substrate and the chip when the sealant layer was formed).

[0161] 〇: The thickness of the sealing layer between the substrate and each chip is less than 40μm.

[0162] ×: The thickness of the sealing layer between the substrate and each chip is 40μm or more.

[0163] The evaluation results are shown in Table 2 below.

[0164] [Example 2]

[0165] In Example 1, dry film 1 was replaced with dry film 2. Otherwise, the mounting substrate was fabricated in the same manner as in Example 1, and the evaluation of suppressing mold marks and the drilling of the sealing layer were performed in the same manner as described above. The evaluation results are shown in Table 2 below.

[0166] [Example 3]

[0167] In Example 1, the organic substrate was changed to a 0.4 mm thick organic substrate on which three types of chips with thicknesses of 165 μm, 220 μm, and 200 μm were mounted with gaps of 10 to 15 μm between them at 0.5 mm intervals. Dry film 1 was changed to dry film 3. Otherwise, the mounting substrate was fabricated in the same manner as in Example 1, and the evaluation of suppressing mold marks and the penetration of the sealing layer were performed in the same manner as described above. The evaluation results are shown in Table 2 below.

[0168] [Comparative Example 1]

[0169] In Example 1, dry film 1 was replaced with dry film 4. Otherwise, the mounting substrate was fabricated in the same manner as in Example 1, and the evaluation of suppressing mold marks and the drilling of the sealing layer were performed in the same manner as described above. The evaluation results are shown in Table 2 below.

[0170] [Comparative Example 2]

[0171] In Example 1, dry film 1 was replaced with dry film 5. Otherwise, the mounting substrate was fabricated in the same manner as in Example 1, and the evaluation of suppressing mold marks and the drilling of the sealing layer were performed in the same manner as described above. The evaluation results are shown in Table 2 below.

[0172] [Table 2]

[0173]

[0174]

[0175] As can be clearly seen from Table 2, using T:t n In mounting substrates (Examples 1 to 3) in which a curable resin composition containing a colorant in a ratio of 10:1.0 to 10:5.0 and a mass percentage of 0.60 to 4.0% by weight forms a sealing layer, the generation of mold marks can be suppressed even in the case of multiple semiconductor chips with different mounting sizes.

[0176] On the other hand, it can be seen that even when T:t is made n When the sealing layer is formed in a ratio of 10:1.0 to 10:5.0, if a curable resin composition that does not contain colorant in a ratio of 0.60 to 4.0% by mass is not used to form the sealing layer, the generation of mold marks cannot be suppressed (Comparative Example 1).

[0177] Furthermore, it is known that in mounting substrates where a sealing layer is formed using a curable resin composition that does not contain a colorant in a proportion of 0.60 to 4.0% by mass, even when the T:t ratio is used... n Even when a thickness greater than 10:5.0 is formed, the generation of mold marks cannot be suppressed (Comparative Example 2).

Claims

1. A mounting substrate comprising: substrate; Multiple semiconductor chips are mounted on at least one surface of the substrate; and A sealing layer covers the substrate surface on which the plurality of semiconductor chips are mounted. The feature of mounting substrate is that In the thickness direction of the mounting substrate, the thickness of the sealing layer is defined as T, and the distance from the upper surface of each semiconductor chip mounted on the substrate to the surface of the sealing layer is defined as t. n In the case of T:t n The ratio is between 10:1.0 and 10:5.

0. The sealing layer is formed from a cured product of a curable resin composition containing a colorant in a proportion of 0.60 to 4.0% by mass.

2. The mounting substrate according to claim 1, wherein, The tn is greater than 50 μm.

3. The mounting substrate according to claim 1, wherein, The T is 100 to 500 μm.

4. The mounting substrate according to claim 1, wherein, The curable resin composition further comprises a thermosetting resin.

5. The mounting substrate according to claim 1, wherein, The colorant comprises carbon black and titanium black.

6. The mounting substrate according to claim 1, wherein, The curable resin composition further comprises a thermoplastic resin having a glass transition temperature below 20°C and a weight-average molecular weight of 30,000 or more.

7. The mounting substrate according to claim 5, wherein, The colorant contains carbon black and titanium black in a ratio of 1:1.1 to 1:7 by mass.

8. The mounting substrate according to claim 1, wherein, Three to six of the semiconductor chips constitute a unit, with the distance between adjacent units being less than 1 mm.

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