Electronic component mounting substrate and method of manufacturing the same, electronic component covering sheet and laminated sheet

Abstract

The present invention provides an electronic component coating sheet capable of forming a high-quality coating layer capable of improving the occurrence of wrinkles and breakage and suppressing misalignment of the coating position, an electronic component mounting substrate having a coating layer, and a method for manufacturing the same. As an electronic component coating sheet (4) for forming the coating layer (3) of an electronic component mounting substrate (10) having a substrate (1), an electronic component (2), and a coating layer (3), the electronic component coating sheet (4) is configured such that (i) the fracture elongation measured at a tensile speed of 50 mm / min at Tg to Tg + 40°C is 800 to 2000%, (ii) the fracture elongation measured at a tensile speed of 1000 mm / min at Tg to Tg + 40°C is 500 to 1500%, and (iii) the puncture strength per unit film thickness at 23°C measured by a puncture test in accordance with JIS Z1707 is 10 to 200 N / mm.

Description

Technology Field

[0001] The present disclosure relates to an electronic component mounting substrate and a method for manufacturing the same. It also relates to an electronic component covering sheet and a laminated sheet. Background Technology

[0002] Electronic components, such as IC chips mounted on the substrate, are protected by a coating layer. The coating layer enhances the substrate's resistance to bending and protects it from physical shock or temperature changes.

[0003] The formation of the coating layer is being replaced by a heat-meltable electronic component coating sheet instead of the conventional conformal coating. For example, Patent Document 1 discloses a method for encapsulating electronic components by coating an electronic component mounted on a substrate with a sheet made of a thermosetting resin composition and heat-curing it. Patent Document 2 discloses a method for manufacturing an encapsulating film having an insulating layer and an electromagnetic shielding layer. The encapsulating film has an elongation rate of 150 to 3500% at the softening point and pre-forms irregularities corresponding to irregularities formed on the substrate on which the electronic component is mounted. Prior art literature

[0004] Japanese Patent Publication No. 2012-054363 Japanese Patent Publication No. 2019-021757 The problem to be solved

[0005] As a method for applying a film in a three-dimensional shape, the Three-Dimensional Overlay Method (TOM) is known, for example. The TOM method allows for coating to follow an uneven shape and can impart various functions such as decorative properties and insulation, so it is used for decorative purposes, such as in automotive interior parts. Since the TOM method is suitable for coating in three-dimensional shapes, it is also promising as a coating layer for substrates mounted on electronic components. However, because electronic components are small and components of different shapes and heights are densely mounted, coating defects such as wrinkling or breakage of the coating layer are prone to occur. Coating defects lead not only to appearance defects but also to quality and performance degradation. In the case of coating layers requiring insulation, they can be a cause of insulation failure in the substrate mounted on the electronic components. Furthermore, in the case of coating layers requiring electromagnetic shielding, a degradation of shielding performance may occur. These problems can become more severe due to miniaturization and thinning. Additionally, if misalignment of the coating layer formation location can be prevented, options such as coating only in areas where it is required become available. Moreover, a significant increase in versatility can also be expected.

[0006] Furthermore, although the above was described in terms of problems in TOM molding, similar problems may arise in vacuum molding, pressure molding, vacuum pressure molding, press molding, injection molding, etc.

[0007] The present disclosure is made in consideration of the above-mentioned problems, and the purpose is to provide an electronic component coating sheet, a laminated sheet, an electronic component mounting substrate having said coating layer, and a method for manufacturing the same, which can form a high-quality coating layer capable of improving wrinkles and breakage and suppressing misalignment of the coating position. means of solving the problem

[0008] The inventors of the present invention, having repeatedly conducted careful examinations, discovered that the problem of the present disclosure can be solved in the following manner, and thus completed the present disclosure.

[0009] [1]: An electronic component covering sheet for forming the covering layer of an electronic component mounting substrate having a substrate, an electronic component mounted on the substrate, and a covering layer covering at least a portion of the electronic component and the substrate,

[0010] (i) the electronic component coating sheet at room temperature is introduced at a temperature of Tg to Tg + 40°C, and the elongation at break measured at a tensile speed of 50 mm / min at the above temperature is 800 to 2000%, and

[0011] (ii) The electronic component coating sheet at room temperature is subjected to a temperature of Tg to Tg + 40°C, and the elongation at break measured at a tensile speed of 1000 mm / min at the said temperature is 500 to 1500%, and also,

[0012] (iii) The electronic component coating sheet, wherein the puncture strength per unit film thickness at 23°C measured by a puncture test in accordance with JIS Z1707 is 10 to 200 N / mm.

[0013] [2]: The above electronic component coating sheet at room temperature is placed under a temperature of Tg to Tg + 40°C, and the Young's modulus E is measured at a tensile speed of 50 mm / min at the above temperature. 50 class,

[0014] The above electronic component coating sheet at room temperature is introduced under a temperature of Tg to Tg + 40°C of the electronic component coating sheet, and the Young's modulus E measured at a tensile speed of 1000 mm / min at the said temperature 1000 Department's non-E 1000 / E 50The electronic component covering sheet described in [1] is 0.8 or higher.

[0015] [3]: A thermosetting resin and a curable compound, wherein the curable compound is a curable compound (c1) having three or more functional groups and an N atom, and

[0016] An electronic component covering sheet described in [1] or [2] containing a difunctional, curable compound (c2) that does not have an N atom.

[0017] [4]: A laminated sheet having a support layer and an electronic component covering sheet described in any one of [1] to [3].

[0018] [5]: A laminated sheet described in [4] having a release layer between the support layer and the electronic component covering sheet.

[0019] [6]: When the Tg of the above support layer is set to Tg2 and the Tg of the above electronic component covering sheet is set to Tg1,

[0020] |Tg2- Tg1| ≤ 20℃

[0021] Laminated sheets described in [4] or [5] that are in relation to each other.

[0022] [7]: An electronic component mounting substrate having a substrate, an electronic component mounted on the substrate, and a covering layer covering at least a portion of the electronic component and the substrate,

[0023] The above coating layer is an electronic component mounting substrate formed using an electronic component coating sheet described in any one of [1] to [3].

[0024] [8]: A method for manufacturing an electronic component mounting substrate comprising a substrate, an electronic component mounted on the substrate, and a covering layer covering at least a portion of the electronic component and the substrate,

[0025] A method for manufacturing an electronic component mounting substrate having a coating process for forming a coating layer using an electronic component coating sheet described in any one of [1] to [3], wherein the coating process is performed by any one of TOM molding, vacuum molding, pressure molding, vacuum pressure molding, press molding, and injection molding.

[0026] [9]: A method for manufacturing an electronic component mounting substrate having a substrate, an electronic component mounted on the substrate, and a coating layer covering at least a portion of the electronic component and the substrate, comprising a coating process for forming the coating layer using a laminated sheet described in any one of [4] to [6], and a process for removing a layer other than the coating layer from the laminated sheet after the coating process, wherein the coating process is performed by any one of the following methods: TOM molding, vacuum molding, pressure molding, vacuum pressure molding, press molding, and injection molding. Effects of the invention

[0027] According to the present disclosure, an excellent effect is achieved in that an electronic component coating sheet, a laminated sheet, an electronic component mounting substrate having said coating layer, and a method for manufacturing said can be provided, which can form a high-quality coating layer capable of improving wrinkles and breakage and suppressing misalignment of the coating position. Brief explanation of the drawing

[0028] FIG. 1 is a schematic cross-sectional view showing an example of an electronic component mounting substrate according to a first embodiment. FIG. 2 is a schematic cross-sectional view showing an example of an electronic component coating sheet according to a first embodiment. FIG. 3 is a schematic cross-sectional view showing an example of a manufacturing process of a first embodiment. FIG. 4 is a schematic cross-sectional view showing an example of a manufacturing process of a first embodiment. FIG. 5 is a schematic cross-sectional view showing an example of a manufacturing process of a first embodiment. FIG. 6 is a schematic cross-sectional view showing an example of an electronic component coating sheet according to a second embodiment. FIG. 7 is a schematic cross-sectional view showing an example of a laminated sheet and a manufacturing process according to a third embodiment. FIG. 8 is a schematic cross-sectional view showing an example of a laminated sheet according to a fourth embodiment. FIG. 9 is a cross-sectional view of the section IX-IX of FIG. 8. FIG. 10 is a schematic cross-sectional view showing an example of an electronic component mounting substrate according to a fifth embodiment. FIG. 11 is a schematic top view showing an example of a laminated sheet according to a fifth embodiment. FIG. 12 is a schematic side view showing an example of a substrate mounted with electronic components according to an embodiment. Specific details for implementing the invention

[0029] Hereinafter, an example of an embodiment applying the present disclosure will be described. Each embodiment may be combined arbitrarily. Furthermore, the sizes and ratios of each component in the following drawings are for convenience of explanation and are not limited thereto. Also, in the description "any number A to any number B" in this specification, number A is included as a lower limit value and number B is included as an upper limit value within the said range. Also, "sheet" and "film" are synonymous. Furthermore, the numerical values ​​specified in this specification are values ​​obtained by the method disclosed in the embodiment or example. Also, unless specifically stated otherwise, each component may be used alone or in combination of two or more types.

[0030] 1. First embodiment

[0031] 1-1. Electronic Component Mounting Board

[0032] FIG. 1 shows an example of a schematic cross-sectional view of an electronic component mounting substrate according to a first embodiment of the present disclosure. As shown in FIG. 1, the electronic component mounting substrate (10) of the first embodiment comprises a substrate (1), an electronic component (2) mounted on the substrate (1), and a coating layer (3).

[0033] The substrate (1) may be arbitrarily selected to be capable of mounting electronic components (2) and withstanding molding processes for each application. Electrodes, wiring patterns, vias (not shown), etc. may be arbitrarily provided on the substrate (1). The substrate may be rigid or flexible. Examples include a work board, a mounting module board, a printed circuit board, and a build-up board formed by a build-up method, in which a conductive pattern made of copper foil, etc. is formed on the surface and / or inside.

[0034] The electronic component (2) is mounted on the main surface of the substrate (1). When multiple electronic components are mounted, their respective shapes and heights may be the same or different. Specific examples of the electronic component (2) include an IC chip, a multilayer ceramic chip capacitor (MLCC), an inductor, and a thermistor.

[0035] The coating layer (3) is applied from the upper surface of the electronic component (2) to the side surface, and also over the entire exposed surface of the main surface of the substrate (1). That is, it is applied to the stepped portion (uneven portion) formed by mounting the electronic component (2), and the coating layer (3) is provided over the entire exposed surface on the main surface of the substrate (1). The coating layer (3) is formed using the electronic component coating sheet of the present disclosure (hereinafter also referred to as the coating sheet). The method of forming the coating layer (3) from the coating sheet is not limited, but any one of the following three-dimensional surface coating methods is preferred: TOM (Three Dimension Overlay Method) molding method, vacuum molding method, pressure molding method, vacuum pressure molding method, press molding method, and injection molding method. Among these, the coating sheet is particularly preferred for TOM molding.

[0036] The coating layer (3) is formed as a single layer or a multilayer. The coating layer may be provided with functions according to needs. For example, it may be composed of an insulating layer, a conductive layer, a thermal conductive layer, a waterproof layer, a shielding layer, a coloring layer, a flame retardant layer, a hard coat layer, an edible layer, etc. For example, a single or multilayer insulating layer, a single or multilayer conductive layer, or a coating layer of an insulating layer / conductive layer may be provided. In addition to protecting the exposed surface of the main surface of the substrate (1) with the coating layer (3), the side of the substrate (1) may also be protected with the coating layer (3) as shown in FIG. 1.

[0037] In the example of FIG. 1, an example in which an electronic component (2) is mounted on one side of a substrate (1) has been described, but an electronic component may be mounted on both sides of the substrate and both sides of the substrate may be covered by a covering layer. In addition, the covering layer may be provided only partially, such as in the electronic component mounting substrate of the fifth embodiment described later, rather than on the entire exposed surface of the main side of the substrate (1).

[0038] 1-2. Electronic Component Covering Sheet

[0039] The electronic component covering sheet of the present disclosure (the covering sheet) is a sheet for forming a covering layer of an electronic component mounting substrate as described above. The covering sheet can provide specific functions in addition to physically protecting the electronic component. Preferred examples of the covering sheet include an insulating sheet having insulating properties, a conductive sheet functioning as an electromagnetic shield layer, a thermally conductive sheet dissipating heat from the electronic component, a shielding sheet preventing the electronic component from being visible or blocking light, a moisture-proof sheet protecting the electronic component from moisture, an embossed sheet, a flame-retardant sheet having flame-retardant properties, a protective sheet having hard-coat properties, and a sheet having any combination of these functions. Preferred examples of a covering sheet having multiple functions include a covering sheet having both insulating and thermal conductivity, a covering sheet having both insulating and shielding properties, a covering sheet having both conductive and shielding properties, and a covering sheet having both insulating and moisture-proof properties.

[0040] The coating sheet may be single-layer or multi-layer. In the case of a multi-layer, multiple layers having the same function may be laminated, or layers with different functions may be laminated. For example, a coating sheet having a laminated configuration of an insulating layer / conductive layer, an insulating layer / hard coat layer, an insulating layer / waterproof layer, or a thermal conductive layer / insulating layer may be exemplified.

[0041] FIG. 2 shows a schematic cross-sectional view of an example of an electronic component covering sheet according to a first embodiment. As shown in FIG. 2, the covering sheet (4) of the first embodiment has a laminated structure of an insulating layer (31) and a conductive layer (32). By placing the insulating layer (31) on the side of the electronic component (2), the electronic component can be insulated and protected, and the conductive layer (32) provided on the upper layer can provide, for example, electromagnetic shielding properties. The ground (not shown) of the conductive layer (32) and the substrate (1) may be electrically connected by a pin (not shown), etc. Alternatively, the conductive layer (32) may be placed on the side of the electronic component (2), and the insulating layer (31) may be placed on the upper layer.

[0042] The present coating sheet is a precursor article of a coating layer and satisfies the following (i) to (iii). In the case of a multilayer, each layer does not need to satisfy (i) to (iii), but the coating sheet satisfies (i) to (iii).

[0043] (i) When an electronic component coating sheet at room temperature is introduced at a temperature of Tg to Tg + 40°C, and the elongation at break is measured at a tensile speed of 50 mm / min at the above temperature, the elongation at break is 800 to 2000%.

[0044] (ii) When an electronic component coating sheet at room temperature is introduced at a temperature of Tg to Tg + 40°C, and the elongation at break is measured at a tensile speed of 1000 mm / min at the above temperature, the elongation at break is 500 to 1500%.

[0045] (iii) The puncture strength per unit film thickness at 23°C, measured by a puncture test in accordance with JIS Z1707 for electronic component coating sheets, is 10 to 200 N / mm.

[0046] In addition, the Tg of the present disclosure is a value obtained by the method of the present embodiment. Also, "Tg to Tg + 40°C" is a condition for indicating the characteristics of the electronic component coating sheet, and the temperature when forming the coating layer is not limited to this range. In addition, the values ​​of (i) to (iii) above are values ​​obtained when performed using the method and conditions described in the embodiments described later.

[0047] Breaking elongation refers to the value of permanent elongation after the coating sheet breaks when a tensile test is performed on the coating sheet. The value of breaking elongation was determined by the method specified in JISK 7161:1994.

[0048] In the present coating sheet, by making the break elongation of (i) above 800% or more and the break elongation of (ii) above 500% or more, the elongation of the coating sheet can be improved and the tearing of the coating layer can be suppressed. Meanwhile, by making the break elongation of (i) above 2000% or less and the break elongation of (ii) above 1500% or less, the occurrence of wrinkles can be suppressed.

[0049] In the present coating sheet, the control for satisfying (i) and (ii) above can be adjusted by the type of curable compound in the composition forming the present coating sheet. Specifically, it can be adjusted by the number of functional groups and equivalent weight of the curable compound. It can also be adjusted by the content ratio of the curable compound in the composition. Furthermore, it can be adjusted by the type, amount, and particle size of the filler. It can also be adjusted by plasticizers, inert resins or oligomers that are not reactive themselves, and flexibility modifiers that do not contribute to crosslinking.

[0050] The puncture strength is a value obtained from a puncture test (23°C) in accordance with JIS Z1707, and specifically, it is the strength when a stainless steel rod (diameter 1 mm) is dropped vertically onto the coating sheet and the coating sheet is torn. The puncture strength per unit film thickness is the puncture strength divided by the thickness of the electronic component coating sheet. By satisfying the above (iii) with the puncture strength per unit film thickness, the breakage of the coating sheet at the edge of the electronic component can be effectively prevented, and a coating sheet of high quality can be provided.

[0051] Control to satisfy (iii) above can be easily adjusted by the crosslinking density of the coating layer. It is preferable to adjust the number of functional groups and equivalent weight of the curable compound in the composition for forming the coating sheet. It is preferable that the curable compound has two or more functional groups, and it is more preferable to contain a curable compound with three to four functional groups. It can also be adjusted by the content ratio of the curable compound in the composition. In addition, it can be adjusted by the type, amount, and particle size of the filler. Furthermore, it can be adjusted by the type of plasticizer, inert resin or oligomer that does not contribute to crosslinking, and other flexibility modifiers.

[0052] By satisfying (i) and (ii) above, the occurrence of wrinkles in the coating layer during a pressure reduction process such as TOM molding can be effectively suppressed. Furthermore, by satisfying (i) and (ii) and also satisfying (iii), breakage of the sheet at the edge can be effectively prevented when heat and stress are applied to the coating sheet, or when the substrate on which electronic components are mounted is subjected to impact. Additionally, misalignment of the stacking position can be suppressed. As a result of these, the quality of the coating sheet can be significantly improved. Additionally, appearance defects can be effectively improved. Therefore, according to the present coating sheet, an electronic component mounting substrate having a coating layer of excellent quality can be provided, including a substrate on which electronic components of different heights are mounted.

[0053] The fracture elongation of (i) above is more preferably 900 to 1700% and more preferably 1000 to 1500% in terms of preventing tearing and wrinkling of the coating layer. By making it 900% or more, the strength of the coating sheet can be increased further, and tearing of the coating layer can be prevented more effectively.

[0054] The fracture elongation of (ii) above is more preferably 650 to 1400% and more preferably 800 to 1300% in terms of inhibiting tearing and wrinkling of the coating layer. The puncture strength per unit film thickness of (iii) above is more preferably 50 to 170 N / mm and more preferably 70 to 150 N / mm in terms of inhibiting tearing of the coating layer.

[0055] If the coating sheet contains a thermosetting resin, it becomes a coating layer through a curing process by heating the electronic component coating sheet. For surface protection, the electronic component coating sheet may be provided with a release sheet on one or both sides.

[0056] In addition, regarding the suppression of tearing of the coating layer and improvement of conformability to the substrate, the coating sheet of the present invention is subjected to a temperature of Tg to Tg + 40°C of the electronic component coating sheet, and the Young's modulus E measured at a tensile speed of 50 mm / min at said temperature 50 It is preferably 1 to 18 GPa, more preferably 3 to 15 GPa, and more preferably 6 to 12 GPa. Likewise, the present coating sheet at room temperature is introduced under a temperature of Tg to Tg + 40°C of the electronic component coating sheet, and the Young's modulus E measured at a tensile speed of 1000 mm / min at said temperature 1000 It is preferable that the Young's modulus be 2 to 20 GPa, more preferable that it be 4 to 18 GPa, and more preferable that it be 6 to 15 GPa. It is believed that by setting the Young's modulus during high-speed tensile testing to the above range, the sheet does not bend during TOM forming, and thus wrinkles can be suppressed.

[0057] The method for adjusting the Young's modulus to the above range can be, for example, by adjusting the crosslinking density. Specifically, this can be done by adjusting the number of functional groups and equivalent weight of the curable compound in the composition for forming the coating sheet. It can also be adjusted by the content ratio of the curable compound in the composition. Furthermore, it can be adjusted by the type, amount, and particle size of the filler. Additionally, it can be adjusted by the type of plasticizer, inert resin or oligomer, or other flexibility modifiers that do not contribute to crosslinking.

[0058] Young's modulus E 1000 Young's modulus E 50 Of E 1000 / E 50 0.8 or higher is desirable. Non-E 1000 / E 50 0.9 or higher is more desirable. Non-E 1000 / E 50 The upper limit of is preferably 1.4 or less, and more preferably 1.3 or less. Non-E 1000 / E50 By making the range as described above, breakage of the sheet at the uneven parts of the electronic component, particularly at the edges, can be prevented, thereby preventing appearance defects more effectively.

[0059] The Tg of the coating sheet is preferably in the range of 0 to 80°C and more preferably 15 to 45°C from the perspective of inhibiting tearing and wrinkling of the coating layer. In the case of a multilayered coating sheet, it is preferable that the Tg of each layer be within the above range. In the case of a multilayered sheet, the Tg is based on the Tg of the layer with the highest Tg.

[0060] The thickness of the coating sheet can be appropriately designed according to the application. For applications where thinning is required, the thickness of the coating sheet covering the top and side surfaces of an electronic component is preferably in the range of 10 to 1000 μm, more preferably in the range of 15 to 500 μm, and more preferably in the range of 20 to 250 μm.

[0061] When this coating sheet is used as an insulating layer, the surface resistance value is 1.0 × 10 7 It is desirable that it be Ω / □ or greater, and 1.0 × 10 8 It is more desirable that it be Ω / □ or greater, and 1.0 × 10 9 It is more preferable that it be Ω / □ or higher. When this coating sheet is used as a conductive layer, the surface resistance value is 1.0 × 10 5 It is preferable that it be Ω / □ or less, and 1.0 × 10 3 It is more preferable that it be Ω / □ or less, and 1.0 × 10 2 It is more desirable that it be Ω / □ or less.

[0062] The present coating sheet comprises a binder component. The binder component is a component that serves as the substrate of the coating layer. Examples of resins used for the binder component include thermosetting resins, photocurable resins, and mixtures thereof. Curable compounds that crosslink with these resins are also included in the binder component. Regarding the thermosetting resin, in addition to self-crosslinking thermosetting resins, thermosetting resins capable of reacting with curable compounds are preferred. A combination of these may also be used. As for the binder resin, a combination of a thermosetting resin and a curable compound is preferred. When using a curable compound, a thermosetting resin having reactive functional groups capable of reacting with the curable compound is preferred. The binder resin may be used alone or in combination of two or more types.

[0063] Thermosetting resins have curable compounds or reactive functional groups that self-crosslink. Examples of functional groups include phenolic hydroxyl groups, acid anhydride groups, methoxymethyl groups, carboxyl groups, amino groups, epoxy groups, oxetanyl groups, oxazoline groups, oxazine groups, aziridine groups, thiol groups, isocyanate groups, blocked isocyanate groups, blocked carboxyl groups, silanol groups, etc.

[0064] Examples of thermosetting resins include polyurethane resin, polyurethaneurea resin, phenoxy resin, acrylic resin, polyester resin, polyamide resin, epoxy resin, polystyrene resin, polycarbonate resin, polyamideimide resin, polyesteramide resin, polyetherester resin, alkyd resin, polyimide resin, benzoxazine resin, amino resin, polylactic acid resin, oxazoline resin, silicone resin, and fluoropolymer resin. Among these, epoxy resin, polyurethane resin, polyurethaneurea resin, polycarbonate resin, phenoxy resin, polyimide resin, polyamideimide resin, and polyamide resin are preferred.

[0065] The acid value of the thermosetting resin is preferably 3 to 30 mgKOH / g from the perspective of improving edge coverage. More preferably, it is 4 to 20 mgKOH / g, and more preferably 5 to 10 mgKOH / g.

[0066] The curable compound has a functional group capable of reacting with the thermosetting resin. It is preferable to have multiple such functional groups. Examples of curable compounds include epoxy compounds, isocyanate compounds, polycarbodiimide compounds, aziridine compounds, compounds containing acid anhydrides, amine compounds such as dicyandiamide compounds and aromatic diamine compounds, phenol compounds such as phenol novolak resins, and organometallic compounds. The curable compound may be a resin or a low-molecular-weight compound. When a resin is used as the curable compound, the thermosetting resin and the curable compound are distinguished by having a higher content as the thermosetting resin and a lower content as the curable compound. The curable compound may be used as a single type or in combination of two or more types.

[0067] In terms of effectively suppressing wrinkles and breakage of the coating layer, a combination of a curable compound (c1) having three or more functional groups and an N atom (hereinafter also referred to as curable compound (c1)) and a curable compound (c2) having two functional groups and not containing an N atom in the functional group (hereinafter also referred to as curable compound (c2)) is preferred. By using the curable compound (c1), the curing reaction prior to the curing process can be promoted to some extent, thereby effectively preventing breakage of the coating sheet during elongation in TOM molding, etc. On the other hand, by using the curable compound (c2), the crosslinking density can be suppressed, allowing crosslinking to proceed slowly, so that breakage elongation during TOM molding, etc. can be maintained well.

[0068] Preferred examples of the curable compound (c1) include trifunctional glycidylamine and trifunctional aziridine. Additionally, preferred examples of the curable compound (c2) include difunctional epoxy compounds.

[0069] Examples of trifunctional or higher glycidylamines include N-glycidides obtained by reacting an aromatic amine (such as aniline and toluidine) having 6 to 20 carbon atoms and 2 to 4 active hydrogen atoms with epichlorohydrin. Specifically, tetraglycidylaminephenylmethane, triglycidyl-p-aminophenol, and tetraglycidyl-m-xylenediamine are also preferred. Examples of commercially available products include Sumiepoxy ELM-100, ELM-120 (manufactured by Sumitomo Chemical Company, Limited), MY721 (manufactured by Ciba Specialty Chemicals Corp.), TETRAD-X and TETRAD-C manufactured by Mitsubishi Gas Chemical Company, Inc., and GAN manufactured by Nippon Kayaku Co., Ltd.

[0070] As trifunctional or higher aziridines, trifunctional aziridines such as trimethylolpropane tris(3-(2-methyl-1-aziridyl)propionic acid) ester, trimethylolpropane tris(3-(1-aziridyl)propionic acid) ester, pentaerythritol tris(3-(2-methyl-1-aziridyl)propionic acid) ester, pentaerythritol tris(3-(1-aziridyl)propionic acid) ester, dipentaerythritol tris(3-(1-aziridyl)propionic acid) ester, and sorbitol tris(3-(1-aziridyl)propionic acid) ester; Examples include tetrafunctional aziridines such as pentaerythritol tetrakis(3-(1-aziridyl)propionic acid) ester, sorbitol tetrakis(3-(1-aziridyl)propionic acid) ester, and ditrimethylolpropane tetrakis(3-(1-aziridyl)propionic acid) ester; pentafunctional aziridines such as sorbitol pentakis(3-(1-aziridyl)propionic acid) ester and dipentaerythritol pentakis(3-(1-aziridyl)propionic acid) ester; and hexafunctional aziridines such as dipentaerythritol hexakis(3-(1-aziridyl)propionic acid) ester and sorbitol hexakis(3-(1-aziridyl)propionic acid) ester.

[0071] As difunctional epoxy compounds, bisphenol-based diglycidyl ethers such as bisphenol A diglycidyl ether, bisphenol F diglycidyl ether, bisphenol E diglycidyl ether, bisphenol Z diglycidyl ether, bisphenol S diglycidyl ether, bisphenol AD ​​diglycidyl ether, bisphenol acetophenone diglycidyl ether, bisphenol trimethylcyclohexane diglycidyl ether, bisphenol fluorene diglycidyl ether, tetramethylbisphenol A diglycidyl ether, tetramethylbisphenol F diglycidyl ether, tetra-t-butylbisphenol A diglycidyl ether, and tetramethylbisphenol S diglycidyl ether; Biphenol diglycidyl ethers such as biphenol diglycidyl ether, tetramethylbiphenol diglycidyl ether, dimethylbiphenol diglycidyl ether, tetra-t-butylbiphenol diglycidyl ether, etc.; benzenediol diglycidyl ethers such as hydroquinone diglycidyl ether, dihydroanthracene diglycidyl ether, methylhydroquinone diglycidyl ether, dibutylhydroquinone diglycidyl ether, resorcinol diglycidyl ether, methylresorcinol diglycidyl ether, etc.; aromatic diglycidyl ethers such as dihydroanthrahydroquinone diglycidyl ether, dihydroxydiphenyl ether diglycidyl ether, thiodiphenol diglycidyl ether, dihydroxynaphthalene diglycidyl ether, etc.; An epoxy compound obtained by adding hydrogen to the aromatic ring of a diglycidyl ether selected from the above bisphenol-based diglycidyl ethers, biphenol-based diglycidyl ethers, benzenediol-based diglycidyl ethers, and aromatic diglycidyl ethers; an epoxy resin prepared from various carboxylic acids such as adipic acid, succinic acid, phthalic acid, tetrahydrophthalic acid, methylhexahydrophthalic acid, terephthalic acid, isophthalic acid, orthophthalic acid, biphenyldicarboxylic acid, and dimer acid, and epihalohydrin;(Poly)alkylene glycol diglycidyl ethers consisting solely of chain structures such as ethylene glycol diglycidyl ether, polyethylene glycol diglycidyl ether, propylene glycol diglycidyl ether, polypropylene glycol diglycidyl ether, 1,4-butanediol diglycidyl ether, polytetramethylene glycol diglycidyl ether, 1,5-pentanediol diglycidyl ether, polypentamethylene glycol diglycidyl ether, 1,6-hexanediol diglycidyl ether, polyhexamethylene glycol diglycidyl ether, 1,7-heptanediol diglycidyl ether, polyheptamethylene glycol diglycidyl ether, 1,8-octanediol diglycidyl ether, 1,10-decanediol diglycidyl ether, 2,2-dimethyl-1,3-propanediol diglycidyl ether, etc.; Examples include alkylene glycol diglycidyl ethers having a cyclic structure, such as 1,4-cyclohexanedimethanol diglycidyl ether. Examples of commercially available products include EPICLON 830, 840, 850, 860, 1050, 2050, 3050, 4050, 7050, HM-091, and 101 manufactured by DIC Corporation, and DENACOL EX-211, 212, 252, 711, and 721 manufactured by Nagase Chemtex Corporation.

[0072] In the case of a heat press, a cross-linked structure can be obtained by thermally cross-linking the epoxy group of the epoxy compound with the carboxyl group or hydroxyl group of the thermosetting resin. As for the epoxy compound, an epoxy compound in liquid form at room temperature (25°C) is also preferred. Specific examples include liquid bisphenol-type epoxy resins such as “R140P” (epoxy equivalent 188) manufactured by Mitsui Chemicals, Inc., “DER383” manufactured by The Dow Chemical Company, and “Epikote #807” (epoxy equivalent 170) manufactured by JER.

[0073] The content of the curable compound (c1) is preferably 0.1 to 7 parts by mass and 0.2 to 5 parts by mass with respect to 100 parts by mass of the thermosetting resin r. In addition, the content of the curable compound (c2) is preferably 1 to 50 parts by mass and 5 to 30 parts by mass with respect to 100 parts by mass of the thermosetting resin r. In addition, the ratio of the curable compound (c2) to the curable compound (c1) is preferably 3 to 150 and more preferably 3 to 50. By maintaining the above ranges, a strong cross-linked structure is formed in the coating layer, and at the same time, excessive curing of the coating layer is suppressed, thereby increasing the ductility for uneven shapes. Furthermore, in the TOM molding method, a coating layer capable of effectively suppressing wrinkles and breakage can be formed.

[0074] The present coating sheet may further include fillers. Insulating fillers are used when insulation is required, conductive fillers are used when conductivity is required, and electromagnetic wave absorbing fillers are used when electromagnetic wave absorption is required. The shape of the filler can be appropriately selected. Examples include flake-shaped, needle-shaped, spherical, dendrite-shaped, and fibrous fillers. Fillers of different shapes may be used in combination. As a preferred example, a combination of flake-shaped fillers and dendrite-shaped fillers may be used.

[0075] The average particle size D50 of the filler is preferably 1 to 100 μm, and more preferably 2 to 80 μm. More preferably 3 to 50 μm, and particularly preferably 5 to 20 μm. Likewise, the preferred range of the average particle size D50 of the dendritic conductive filler is also preferably 2 to 100 μm, and more preferably 2 to 80 μm. More preferably 3 to 50 μm, and particularly preferably 5 to 20 μm.

[0076] The filler content is preferably 1 to 50 mass% with respect to 100 mass% of the coating sheet, from the perspective of inhibiting tearing and wrinkling of the coating layer, and is more preferably 1.5 to 35 mass%. In the case of a multilayer, the total sum of all layers (where n is an integer of 2 or more) of the filler content of n layer × film thickness of n layer / (film thickness of the entire coating layer) is preferably 1 to 50 mass%, and is more preferably 1.5 to 35 mass%.

[0077] Insulating fillers may include, for example, non-metallic inorganic fillers such as silica, alumina, boron nitride, aluminum nitride, magnesium silicon nitride, silicon carbide, titania, glass, and ceramics. Insulating fillers are used either individually or in combination of two or more types.

[0078] Conductive fillers can be exemplified by metal fillers, conductive ceramic fillers, and mixtures thereof. Metal fillers can be exemplified by metal powders such as gold, silver, copper, and nickel; alloy powders such as Hender; and core-shell type fillers of silver-coated copper powder, gold-coated copper powder, silver-coated nickel powder, and gold-coated nickel powder. From the perspective of obtaining excellent conductivity properties, conductive fillers containing silver are preferred. From the perspective of cost, silver-coated copper powder is particularly preferred.

[0079] Examples of electromagnetic wave absorbing fillers include iron alloys such as iron, Fe-Ni alloy, Fe-Co alloy, Fe-Cr alloy, Fe-Si alloy, Fe-Al alloy, Fe-Cr-Si alloy, Fe-Cr-Al alloy, and Fe-Si-Al alloy; ferritic materials such as Mg-Zn ferrite, Mn-Zn ferrite, Mn-Mg ferrite, Cu-Zn ferrite, Mg-Mn-Sr ferrite, and Ni-Zn ferrite; and carbon fillers. Examples of carbon fillers include acetylene black, Ketjen black, furnace black, carbon black, carbon fiber, carbon nanotubes, graphene fillers, graphite fillers, and carbon nanowalls.

[0080] The present coating sheet may include a flexibility modifier. The flexibility modifier can improve wrinkling and tearing during the molding process of the coating sheet. Examples of flexibility modifiers include plasticizers and inert thermoplastic resins.

[0081] Examples of the above plasticizers include fatty acid esters, phthalic acid esters, aromatic polycarboxylic acid esters, and polyesters.

[0082] Examples of fatty acid esters include trioctyl trimellitate (TOTM), manufactured by MGC Trading India Private Limited, butyl stearate, UNISTER M-9676, UNISTER M-2222SL, UNISTER H-476, UNISTER H-476D, PANACET 800B, PANACET 875, PANACET 810 (all manufactured by NOF CORPORATION), DBA, DIBA, DBS, DOA, DINA, DIDA, DOS, BXA, DOZ, DESU (all manufactured by DAIHACHI CHEMICAL INDUSTRY CO., LTD.). Examples of phthalic acid esters include DMP, DEP, DBP, #10, BBP, DOP, DINP, DIDP (hereinafter manufactured by DAIHACHI CHEMICAL INDUSTRY CO., LTD.), PL-200, DOIP (hereinafter manufactured by CG ESTER CORPORATION), and SANSOCIZER DUP (manufactured by New Japan Chemical Co., LTD.). Examples of aromatic polycarboxylic acid esters include TOTM (manufactured by DAIHACHI CHEMICAL INDUSTRY CO., LTD.), MONOCIZER W-705 (manufactured by DAIHACHI CHEMICAL INDUSTRY CO., LTD.), UL-80, and UL-100 (manufactured by ADEKA CORPORATION). Examples of polyesters include POLYCIZER TD-1720, POLYCIZER S-2002, POLYCIZER S-2010 (manufactured by DIC Corporation), and BAA-15 (manufactured by DAIHACHI CHEMICAL INDUSTRY CO., LTD.).

[0083] Among these, DMP, DEP, DBP, DOP, DINP, DIDP, and TOTM are more preferred. Plasticizers are used either alone or in combination of two or more types.

[0084] Examples of the above-mentioned thermoplastic resins include polyolefin resins, vinyl resins, styrene-acrylic resins, diene resins, terpene resins, petroleum resins, cellulose resins, polyamide resins, polyurethane resins, polyester resins, polycarbonate resins, polyimide resins, liquid crystal polymers, and fluoropolymers. Although not particularly limited, polyamide resins, polyurethane resins, polyester resins, polycarbonate resins, polyimide resins, liquid crystal polymers, and fluoropolymers are more preferred from the perspective of heat resistance.

[0085] In addition, the present coating sheet may include a tackifying resin to improve adhesion to the substrate. The tackifying resin is a component that additionally improves adhesive strength, has a weight average molecular weight of less than 5,000, and is distinguished from the thermoplastic resin and binder resin mentioned above. Examples of tackifying resins include rosin-based resins, terpene-based resins, alicyclic petroleum resins, and aromatic petroleum resins.

[0086] The coating sheet may further include a coloring agent, a flame retardant, a lubricant, an anti-blocking agent, etc. Examples of flame retardants include halogen-containing flame retardants, phosphorus-containing flame retardants, nitrogen-containing flame retardants, inorganic flame retardants, etc. Examples of lubricants include fatty acid esters, hydrocarbon resins, paraffin, higher fatty acids, fatty acid amides, aliphatic alcohols, metal soaps, modified silicones, etc. Examples of anti-blocking agents include calcium carbonate, silica, polymethylsilsesquioxane, aluminum silicate salts, etc.

[0087] In the example of FIG. 2, an example of a coating sheet consisting of a multilayer insulating layer (31) and a conductive layer (32) was given, but as described above, a single-layer coating sheet may be used, or a coating sheet consisting of a multilayer having the same function may be used. Additionally, a second layer may be patterned at any location of the first layer. For example, by using a coating sheet in which an insulating layer (31) is patterned at any location of the conductive layer (32), a conductive layer (32) can be formed over the entire exposed surface of one side of the substrate (1), and a coating layer having an insulating layer (31) can be formed at a location where insulation protection is required. According to the present coating sheet, misalignment of the coating work can be effectively prevented, thereby significantly increasing the design freedom of the coating sheet.

[0088] 1-3. Method for manufacturing electronic component coating sheets

[0089] The method for manufacturing the coating sheet is not particularly limited, but, for example, a method of applying a composition in which a material such as the binder resin forming the coating layer is dissolved in a solvent, etc., to a release sheet may be used. Examples of coating methods include gravure coating, kiss coating, die coating, lip coating, comma coating, blade coating, roll coating, knife coating, spray coating, bar coating, spin coating, dip coating, or various printing methods. In the case of a multilayer, known methods such as a lamination method or a method of laminating using an adhesive may be applied.

[0090] 1-4. Applications of Electronic Component Coating Sheets

[0091] The present coating sheet may be particularly preferably used for coating substrates mounted on electronic components, but may also be used for coating other items to be coated. An electronic component-mounted substrate using the present coating sheet is preferably provided in electronic devices such as notebook PCs, mobile phones, smartphones, and tablet terminals, in addition to liquid crystal displays and touch panels.

[0092] 1-5. Method for manufacturing an electronic component mounting board

[0093] An example of TOM molding is described as a method for manufacturing an electronic component mounting substrate using the present coating sheet. However, the method for manufacturing the electronic component mounting substrate is not limited to the following. The coating layer may be formed from the present coating sheet by a method other than the TOM molding method (e.g., vacuum molding, pressure molding, vacuum pressure molding, press molding, injection molding). For example, a coating layer may be formed from the present coating sheet by the method described in Japanese Patent No. 7193031.

[0094] The method for manufacturing an electronic component mounting substrate comprises a process of mounting one or more electronic components onto a substrate (Process A), a process of preparing an electronic component covering sheet cut to a predetermined size (Process B), and a covering process of forming a covering layer using the covering sheet or a laminated sheet having the covering sheets laminated therein (Process C), thereby obtaining an electronic component mounting substrate protected by a covering layer formed by the electronic component covering sheet of the present disclosure. Hereinafter, Process C will be explained using the schematic manufacturing process diagrams of FIGS. 3 to 5.

[0095] First, a substrate (1) with an electronic component (2) mounted thereon is placed on a stage (5) in the lower space (21) of a box (20) having a lower space (21) and an upper space (22). Next, a coating sheet (4) is placed on a partition plate (6) to partition the space between the upper space (22) and the lower space (21) (see FIG. 3). Then, the inside of the box (20) is vacuumed, and the coating sheet (4) is softened by heating it with a heating source (7) up to the Tg range of the coating sheet (4). The Tg range is, for example, a range of Tg ± 20℃. Also, if the coating sheet (4) is multilayer, the Tg of the layer with the highest Tg is used as the reference. Additionally, it is preferable to be able to fix the coating sheet (4), and a fixing jig that places the sheet between may be used instead of a partition plate.

[0096] As the temperature of the coating sheet (4) approaches the Tg surrounding temperature due to heating by the heating source (7), the flatness of the coating sheet (4) is lost and waves appear (see FIG. 4). Furthermore, as heating continues, the waves of the coating sheet (4) decrease, and the coating sheet (4) bends around the center due to its own weight (see FIG. 5). By heating the coating sheet (4) until it reaches this state, the formation of wrinkles in the coating layer can be effectively prevented, thereby improving quality. In addition, to increase the adhesion of the coating layer to the substrate (1) and the electronic component (2), it is desirable to heat the stage (5) on which the substrate (1) with the electronic component (2) mounted is placed. By heating, the effect of increasing production efficiency during continuous production is obtained. The temperature of the stage (5) during heating is, for example, 50 to 120°C. The temperature of the stage (5) during heating is preferably in the range of Tg ± 20℃ from the perspective of improving continuous productivity.

[0097] If necessary, the stage (5) installed in the lower space (21) is moved upward to bring a part of the coating sheet (4) into contact with or close to the upper surface of the electronic component (2). Then, the surface of the coating sheet (4) is pressurized by air or compressed air from the upper space (22). Then, the coating sheet (4) is harvested along the uneven surface of the substrate (1) on which the electronic component (2) is mounted. Then, the excess coating sheet is removed. If a thermosetting resin is used as the binder resin, a thermosetting treatment is performed, and if a photocurable resin is used, a photocuring treatment is performed. Through these processes, an electronic component-mounted substrate (10) having a coating layer (3) as shown in FIG. 1 is obtained.

[0098] According to the above method, the coating sheet can be cut to match the coating area, and a coating layer can be formed on a substrate with electronic components mounted thereon regardless of the shape or arrangement of the electronic components. In addition, since the coating layer is formed by coating the entire surface with a coating sheet and then the excess coating layer is cut, it has the advantage of not requiring precise positional alignment between the coating sheet and the substrate with electronic components mounted thereon.

[0099] According to the present coating sheet, by satisfying (i) to (iii) above, a high-quality coating layer can be formed even for electronic components that have been made thin and lightweight. According to the TOM molding method, the present coating sheet can be heated by heat and then formed into a three-dimensional uneven shape using a pressure difference while in a softened state, so productivity can be significantly improved.

[0100] 2. Second embodiment

[0101] An electronic component coating sheet according to a second embodiment will be described. As described below, the electronic component coating sheet according to the second embodiment differs from the first embodiment in its layer composition, but its basic structure and manufacturing method are the same as those of the first embodiment. In addition, in the following drawings, elements and components identical to those shown above will be appropriately given the same reference numerals.

[0102] FIG. 6 shows a schematic cross-sectional view of an example of an electronic component covering sheet according to a second embodiment. The electronic component covering sheet (4a) has a first layer (41), a second layer (42), and a third layer (43) that are all insulating layers stacked in this order. The first layer (41), the second layer (42), and the third layer (43) may each independently have the same function or different functions. The preferred components, composition amounts, and characteristics of the first layer, the second layer, and the third layer are the same as those of the first embodiment.

[0103] The first layer (41), which is positioned to face the electronic component, is preferably designed to reduce bending and improve embeddability. The second layer (42) is preferably designed to reduce bending while increasing the ability to follow the three-dimensional shape of the electronic component during TOM molding, etc. For this reason, it is preferable to include a liquid epoxy compound in the curable compounds of the first and second layers.

[0104] A liquid epoxy compound refers to an epoxy compound that becomes liquid at 25°C. Preferred examples include jER (registered trademark (hereinafter omitted)) YL980, jERYL983U, jER152, jER630, jERYX8000 (all trade names, manufactured by Mitsubishi Chemical Corporation), EPICLON (registered trademark), and HP-4032 (all trade names, manufactured by DIC Corporation). Liquid epoxy compounds are used either alone or in combination of two or more types.

[0105] The third layer (43) is preferably designed to serve the role of optimizing hardness in addition to primarily adjusting the film thickness, thereby increasing the durability of the coating sheet. It is preferable to include a filler to increase durability.

[0106] According to the second embodiment, by configuring it as a three-layer structure, the degree of design freedom for each layer can be increased, thereby enabling high functionality of the coating layer. As a result, the adhesion between the coating sheet (4a) and the electronic component (2), etc., is increased, and the water-removal capability is increased, thereby effectively preventing the occurrence of wrinkles in the coating layer and breakage at the edge portion of the coating layer.

[0107] In the second embodiment, an example of a coating sheet composed of three layers was given, but it can be single-layer or multi-layer (two layers, four layers or more) within the scope of not departing from the intent of the present disclosure.

[0108] 3. Third embodiment

[0109] The method for manufacturing an electronic component mounting substrate according to the third embodiment differs from the method for manufacturing the first embodiment in that it uses a laminated sheet having the present coating sheet, but the basic structure of the electronic component mounting substrate and the basic manufacturing method are the same as those of the first embodiment.

[0110] FIG. 7 shows a schematic diagram illustrating an example of a manufacturing process for an electronic component mounting substrate according to a third embodiment. In the first embodiment, a coating sheet (4) was placed on a partition plate (6), but in the third embodiment, a laminated sheet (50) is placed on the partition plate (6). The laminated sheet (50) has a support layer (8) and a coating sheet (4) formed on the support layer (8). The size of the coating sheet (4) is set to the size required to form a coating layer. According to this method, it is possible to omit the process of cutting unnecessary parts after forming the coating layer.

[0111] The method of manufacturing the laminated sheet (50) is not limited, but the method of attaching the coating sheet (4) to a desired location on the support layer (8) is simple. As a preferred method, a method of temporarily attaching the coating sheet (4) to the support layer (8) by heating can be exemplified. The support layer (8) has the role of fixing (fixed by placing it on the partition plate (6) in this example) during the manufacturing process and the role of supporting the coating sheet. The support layer can also be called a peeling layer in that it is peeled off after the coating layer is formed. The laminated sheet (50) is coated onto a substrate (1) on which an electronic component (2) is mounted by the same method as in the first embodiment to form a coating layer (3), and then, the support layer (8) is peeled off to obtain a substrate on which an electronic component is mounted.

[0112] The support layer (8) may have the above functions but is not particularly limited. Preferred examples include polyvinyl chloride (PVC) and polyolefin. The thickness of the support layer (8) is preferably 5 to 500 μm and more preferably 10 to 250 μm from the perspective of improving conformability to the substrate. The Tg of the support layer (8) is preferably 30 to 90°C and more preferably 40 to 80°C from the perspective of improving conformability to the substrate. When the Tg of the coating sheet (4) is set to Tg1 and the Tg of the support layer (8) is set to Tg2,

[0113] |Tg2- Tg1| ≤ 20℃

[0114] It is desirable that the relationship be within this range. By setting it to this range, the following capability regarding uneven shapes caused by electronic components, etc. can be more effectively enhanced. More preferably

[0115] |Tg2- Tg1| ≤ 10℃

[0116] The Tg2 of the support layer can be adjusted according to the type of resin and its manufacturing conditions. It is preferable to set the temperature inside the box (20) to a range of ± 20℃ of the higher of Tg1 and Tg2.

[0117] For positioning the substrate equipped with electronic components and the coating sheet, known methods can be applied without limitation. For example, precise positioning can be achieved by combining the marks on the support layer with the marks on the stage.

[0118] According to the coating sheet of the third embodiment, since there is no need to use a coating sheet (4) of a size that can be placed on the partition plate (6) of the box (20), the loss of the coating sheet (4) can be eliminated, thereby reducing costs. In addition, since the coating sheet (4a) can be adjusted to a desired size depending on the size of the substrate on which the electronic components are mounted, the versatility can be significantly increased. Furthermore, since the coating sheet (4) can be supported by the support layer (8), there is an advantage in that it is easy to realize a thin film of the coating layer.

[0119] 4. Fourth embodiment

[0120] The laminated sheet according to the fourth embodiment differs from the laminated sheet of the third embodiment, which does not have a release layer (9), in that it has a release layer (9) between the support layer (8) and the covering sheet (4a). FIG. 8 shows a schematic plan view showing an example of the laminated sheet according to the fourth embodiment, and FIG. 9 shows a cross-sectional view of the section IX-IX of FIG. 8. As shown in these drawings, the support layer (8), the release layer (9), and the covering sheet (4a) are laminated in this order. The area of ​​each layer is support layer (8) > release layer (9) > covering sheet (4a), and when viewed from the top surface, the outer edge region of the release layer (9) is on the outer side of the covering sheet (4a), and the outer edge region of the support layer (8) is on the outer side of the release layer (9). The support layer (8) is sized to be placed on the partition plate (6), and the covering sheet (4a) is sized to be optimal for forming the covering layer. Additionally, the release layer (9) has an area extending from the end of the covering sheet (4a) to facilitate easy peeling after the covering layer is formed. Preferred examples of the release layer (9) include polypropylene (PP), polyethylene (PE), etc.

[0121] The thickness of the release layer (9) is, for example, about 5 to 1000 μm. From the perspective of improving adherence to the substrate, 5 to 500 μm is preferred, and 10 to 250 μm is more preferred. The Tg of the release layer (9) is preferably -50 to 50°C, and more preferably -20 to 20°C.

[0122] According to the fourth embodiment, by using a release layer (9), the adhesion between the support layer (8) and the covering sheet (4a) is effectively prevented, and damage to the covering layer (3) is prevented, thereby increasing the manufacturing yield. In addition, it becomes possible to significantly increase the selection of materials for the support layer (8). Furthermore, the misalignment of the stacking position can be effectively improved.

[0123] 5. Fifth embodiment

[0124] In the fifth embodiment, the coating layer is provided on a part of one surface of the electronic component mounting substrate, which is different from the first embodiment in that the coating layer is provided on the entire surface of one surface of the electronic component mounting substrate.

[0125] FIG. 10 shows a schematic cross-sectional view of an example of an electronic component mounting substrate according to the fifth embodiment. A coating layer (3a) provided on the electronic component mounting substrate (11) is coated on a portion of the exposed surface of one side of the substrate (1) and the electronic component (2). The partially coated coating layer (3a) can be formed, for example, using a laminated sheet of the third embodiment or the fourth embodiment.

[0126] According to the electronic component mounting substrate of the fifth embodiment, a covering layer can be easily formed at a location requiring protection. Additionally, by using the laminated sheet of the third or fourth embodiment, positional misalignment can be effectively prevented. Furthermore, as shown in FIG. 11, a plurality of covering sheets (4) may be laminated on the support layer (8). According to this method, a plurality of covering layers (3) having the necessary functions can be formed collectively at a desired location according to the functions required of the electronic component mounting substrate.

[0127] Examples

[0128] The present disclosure is described in detail below with reference to examples and comparative examples, but the present disclosure is not limited to the following examples. Also, the following "parts" and "%" are values ​​based on "parts by mass" and "mass%", respectively.

[0129] A. Covering sheet

[0130] The raw materials used in the examples are shown below.

[0131] A-1. Thermosetting resin

[0132] [Synthesis of Thermosetting Resin R1]

[0133] 166 parts of terephthalic acid, 146 parts of adipic acid, 212 parts of 3-methyl-1,5-pentanediol, and 25 parts of ethylene glycol were added to a glass flask equipped with a stirrer, thermometer, reflux condenser, nitrogen inlet tube, and reduced pressure equipment, and stirred while passing nitrogen gas through. The temperature was gradually increased under atmospheric pressure, and the reaction was carried out at 200 to 230°C for about 8 hours to obtain a liquid product with an acid value of 43 mgKOH / g. Next, 0.01 parts of tetra-n-butoxytitanine were added, and after nitrogen substitution, the mixture was stirred at 180°C for 30 minutes under a closed system. Then, the reaction was carried out at 230°C and 5 mmHg for 2 hours to obtain a polyesterdiol with an acid value of 1.1 mgKOH / g, a hydroxyl group of 114.2 mgKOH / g, and a molecular weight of 982. In addition, the acid value and hydroxyl value were obtained by weighing the thermosetting resin, measuring it using the automatic titration device GT-200 manufactured by Mitsubishi Chemical Analytech Co., Ltd. in accordance with the potentiometric titration method of JIS K0070, and converting it to solid content.

[0134] Next, 734 parts of the polyester diol, 23.9 parts of dimethylolpropionic acid, 219 parts of toluene diisocyanate, and 242 parts of toluene were added to a reaction vessel equipped with a stirrer, a thermometer, a reflux condenser, a dropping device, and a nitrogen inlet tube, and the mixture was reacted at 50°C for 8 hours under a nitrogen atmosphere. Thereupon, 1200 parts of toluene were added to obtain a urethane prepolymer solution having isocyanate groups at the terminals.

[0135] Next, the obtained urethane prepolymer solution was heated to 70°C, and while maintaining that temperature, a solution mixed with 20.0 parts of 1,3-diaminopropane, 3.1 parts of benzylamine, 600 parts of 2-pronol, and 961 parts of toluene was added dropwise over a period of 1 hour. After the addition was finished, the reaction was carried out for an additional 6 hours at 70°C to obtain a polyurethane resin having a molecular weight (Mw) of 130,000, an acid value of 10 mgKOH / g, a Tg of 20°C, and a solid content of 25%.

[0136] A-2. Curable Compounds

[0137] Curable compound (c1): Polyfunctional epoxy resin "TETRAD-X", manufactured by Mitsubishi Gas Chemical Company, Inc.

[0138] Curable compound (c2): Epoxy resin “jER828”, difunctional, manufactured by Mitsubishi Chemical Corporation

[0139] A-3. Flexibility Adjuster

[0140] Plasticizer p1: Trioctyl trimellitate, manufactured by MGC Trading India Private Limited

[0141] A-4. Filler

[0142] Filler f1: Silica "ULTRASIL U360" (DBP Oil absorption capacity: 220 mL / 100 g, Volume resistivity: 1.6 × 10⁻⁶ 16 Ω·cm) Manufactured by NANOCYL

[0143] B. Supporters

[0144] Support layer X1: Polyvinyl chloride sheet produced by melt rolling of polyvinyl chloride powder (manufactured by Zeon Corporation), Tg: 76℃

[0145] Support layer X2: Polyvinyl chloride sheet produced by the solvent method using polyvinyl chloride powder (manufactured by Zeon Corporation), Tg: 54℃

[0146] C. Irregular layer

[0147] Release layer Y1: Co-extrusion protective film Eltek MX 157N3U, manufactured by Nihon Matai Co., Ltd., Tg: -1℃

[0148] D. Measurement Method

[0149] D-1. Glass transition temperature Tg

[0150] Tg was measured for the measurement samples (electronic component coating sheets), release layers, and support layers of each example and comparative example using a dynamic viscoelasticity measuring device DVA-200 (manufactured by IT Keisoku Seigyo. Co., Ltd.) in accordance with JIS K7198. For the measurement, the electronic component coating sheets of each example were cut to 0.5 cm × 3 cm and the release film was removed. The deformation mode was tensile, and Tg was defined as the temperature at which the principal dispersion peak of the loss tangent (tanδ) appeared, measured at a strain of 0.08%, a frequency of 10 Hz, and a heating rate of 10°C / min.

[0151] D-2. Elongation at Break and Young's Modulus

[0152] The electronic component coating sheets with attached release films of each example and comparative example, obtained by the method described below, were cut to a size of 20 mm in width × 60 mm in length. Then, by peeling off the release film, a measurement sample (electronic component coating sheet) consisting of a coating sheet was obtained. Each measurement sample (coating sheet) was introduced from room temperature into a temperature of Tg + 40°C (atmosphere, 50% RH), and after 1 minute, a tensile test was performed at the said temperature under conditions of a tensile speed of 50 mm / min and a relative humidity of 50% using a small benchtop tester EZ-TEST (manufactured by Shimadzu Corporation) with an effective tensile size of 20 × 23 mm, and the elongation at fracture at a tensile speed of 50 mm / min was determined. In addition, regarding the stress-strain curve during the above tensile test, the tangent of the linear region prior to the yield point was determined, and Young's modulus E 50 ...was done. Likewise, each measurement sample (coating sheet) was introduced from room temperature to a temperature of Tg (atmosphere, 50%RH), and by the same method, the elongation at break and Young's modulus E 50 Measured.

[0153] Likewise, the coated sheet was introduced from room temperature into an atmosphere of Tg + 40°C, and after 1 minute, a tensile test was performed at the said temperature under conditions of a tensile speed of 1000 mm / min and a relative humidity of 50% with an effective tensile size of 20 × 23 mm, and the elongation at break at a tensile speed of 1000 mm / min was determined. In addition, using the same method with the above apparatus, the Young's modulus E at a test speed of 1000 mm / min 1000 ...was obtained. Likewise, each measurement sample (coated sheet) was introduced from room temperature to a temperature of Tg (atmosphere, 50%RH), and by the same method, the elongation at break and Young's modulus E at a tensile speed of 1000 mm / min were measured. 1000 Measured.

[0154] D-3. Drilling Strength

[0155] Electronic component coating sheets (100 mm × 100 mm) of each example and comparative example were prepared, and the puncture strength per unit film thickness at 23°C was determined by a puncture test in accordance with JIS Z1707. Specifically, the sample was placed in a sample mounting jig having an opening of 80 mm in diameter and installed in a TE-1003 low-temperature high-temperature adhesion peel tester Type II (manufactured by TESTER SANGYO CO., LTD.) equipped with a stainless steel rod (length 17 mm) with a diameter of 1 mm as a measuring probe. Under the condition of a measurement temperature of 23°C, the probe was inserted into the electronic component coating sheet at a speed of 100 mm / min, and the strength at break was recorded and taken as the puncture strength. The puncture strength α per unit film thickness was calculated by dividing the obtained puncture strength value by the thickness of the electronic component coating sheet.

[0156] D-4. Film thickness

[0157] The thickness of the coating layer on the electronic component mounting substrate was determined by performing cross-sectioning by a polishing method and measuring the film thickness at the thickest point in the upper surface area of ​​the electronic component using a laser microscope. The same measurement was performed on five cross-section samples of different electronic component mounting substrates, and the average value was taken as the thickness.

[0158] E. Fabrication of electronic component covering sheets and laminated sheets

[0159] [Example 1]

[0160] 100 parts of thermosetting resin r1 (solid content), 2 parts of curable compound c1, 20 parts of curable compound c2, 5 parts of flexibility modifier, and 22.4 parts of filler f1 were placed in a container, and a mixed solvent of toluene:isopropyl alcohol (mass ratio 2:1) was added so that the non-volatile content concentration was 45 mass%, and the mixture was stirred with a disperser for 10 minutes to obtain a composition. This composition was coated onto a release film (release-treated polyethylene terephthalate film, thickness 50 μm) using a doctor blade so that the dry thickness was 70 μm. Then, the electronic component coating sheet with the release film attached according to Example 1 was obtained by drying at 100°C for 2 minutes.

[0161] After cutting the obtained electronic component coating sheet with a release film attached into 60 mm squares, the release film was peeled off, and a support layer X1 (300 mm squares) having a release function was laminated onto the surface where the release film was laminated, thereby obtaining a laminated sheet according to Example 1 (an electronic component coating sheet having a support layer). The electronic component coating sheet was placed in the center of the support layer X1 when viewed from a planar view.

[0162] [Examples 2–18, Comparative Examples 1–5]

[0163] Laminated sheets (electronic component coating sheets having a support layer) according to Examples 2 to 18 and Comparative Examples 1 to 5 were obtained by the same method except that the mixing amounts of Tables 1 to 3 were changed.

[0164] [Example 19]

[0165] A composition was obtained by adding 100 parts of thermosetting resin r1 (solid content), 2 parts of curable compound c1, 20 parts of curable compound c2, 5 parts of flexibility modifier, and 22.4 parts of filler f1 to a container, adding a mixed solvent of toluene:isopropyl alcohol (mass ratio 2:1) to achieve a non-volatile content concentration of 45 mass%, and stirring with a disperser for 10 minutes. This composition was coated onto a release film (release-treated polyethylene terephthalate film, thickness 50 μm) using a doctor blade to achieve a dry thickness of 70 μm. Then, by drying at 100°C for 2 minutes, a laminate of the release film and the first layer α was obtained.

[0166] Next, 100 parts of thermosetting resin r1 (solid content), 6.7 parts of curable compound c1, 20 parts of curable compound c2, 5 parts of flexibility modifier, and 23.3 parts of filler 1 were placed in a container, and a mixed solvent of toluene:isopropyl alcohol (mass ratio 2:1) was added so that the non-volatile content concentration was 45 mass%, and the mixture was stirred with a disperser for 10 minutes to obtain a composition. The obtained composition was coated onto the first layer α of the release film / first layer α using a doctor blade so that the dry thickness was 70 μm to obtain a second layer β. Then, a laminate of the release film / first layer α / second layer β was obtained by drying at 100°C for 2 minutes.

[0167] After cutting the obtained laminate of the release film / first layer α / second layer β into 60 mm squares, the release film was peeled off, and a support layer X1 (300 mm squares) having a release function was laminated onto the surface where the release film was laminated in the same manner as in Example 1, thereby obtaining the laminated sheet of Example 19 (support layer / first layer α / second layer β). The first layer α / second layer β corresponds to an electronic component coating sheet.

[0168] [Example 20]

[0169] A laminated sheet of Example 20 was obtained by the same method as Example 19, except that the mixing amount was changed.

[0170] [Example 21]

[0171] 100 parts of thermosetting resin r1 (solid content), 6.7 parts of curable compound c1, 20 parts of curable compound c2, 5 parts of flexibility modifier, and 23.3 parts of filler 1 were added to a container, and a mixed solvent of toluene:isopropyl alcohol (mass ratio 2:1) was added so that the non-volatile content concentration was 45 mass%, and the mixture was stirred with a disperser for 10 minutes to obtain the composition. Using a doctor blade, a third layer γ was formed on the second layer β of a release film / first layer α / second layer β so that the dry thickness of the composition was 70 μm. Then, by drying at 100°C for 2 minutes, a laminate consisting of a release film / first layer α / second layer β / third layer γ was obtained.

[0172] After cutting the laminate consisting of the obtained release film / first layer α / second layer β / third layer γ into 60 mm squares, the release film was peeled off, and a support layer X1 (300 mm squares) was laminated as a release layer on the surface where the release film was laminated, thereby obtaining a laminated sheet of the support layer / first layer α / second layer β / third layer γ of Example 21.

[0173] [Example 22]

[0174] A laminated sheet of Example 22 was obtained by the same method as in Example 21, except that the mixing amounts in Table 4 were changed.

[0175] [Example 23]

[0176] A laminated sheet of Example 23 (support layer X2 / first layer α / second layer β / third layer γ) was obtained by the same process as in Example 21, except that a laminate of support layer X2 was used instead of support layer X1.

[0177] [Example 24]

[0178] A laminated sheet of Example 24 (support layer X2 / release layer Y1 / first layer α / second layer β / third layer γ) was obtained by cauterization in the same manner as in Example 23, except that a release layer Y1 was laminated between the support layer X2 and the first layer α.

[0179] F. Fabrication of test substrates

[0180] A substrate was prepared on which mold-sealed electronic components (1 cm × 1 cm) were mounted in an array of 5 × 5 on a substrate made of glass epoxy. The thickness of the substrate was 0.3 mm, and the mold-sealing thickness, i.e., the height (component height) H from the upper surface of the substrate to the top surface of the mold-sealing material, was 0.7 mm. After that, half-dicing was performed along the grooves, which are the gaps between the components, to obtain a substrate with electronic components mounted thereon (see FIG. 12). The depth of the half-cut groove was 0.8 mm (the depth of the cut groove extending the chain on the substrate (1) was 0.1 mm), and the width of the half-cut groove was 200 μm. A line was drawn at the end of a 6 cm × 6 cm area centered on the area where the electronic components were mounted to specify an area for misalignment evaluation.

[0181] G. Evaluation

[0182] G-1. TOM Aptitude

[0183] Samples were arranged so that the pattern positions of the portion of the electronic component covering sheet (6 cm × 6 cm) of the laminated sheet of each example and comparative example and the area for misalignment evaluation (6 cm × 6 cm) on the test substrate overlapped, and overlay molding was performed at a set temperature Tg + 40 using a TOM molding machine (manufactured by Fu-se Vacuum Forming Ltd.). Then, after peeling off the release layer (support layer, or support layer + release layer), post-baking was performed at 180°C for 60 minutes to obtain an electronic component mounting substrate. The appearance of the obtained electronic component mounting substrate was evaluated based on the following criteria regarding wrinkles and tearing.

[0184] G-2. Wrinkles

[0185] The number and length of wrinkles present in the electronic component coating layer on the electronic component-mounted substrate were measured and evaluated according to the following criteria.

[0186] ++++: The number of wrinkles is 0 to 2, and the length of each wrinkle is less than 3 mm.

[0187] ++: The number of wrinkles is 0 to 2, and the length of each wrinkle is 3 mm or more and less than 5 mm.

[0188] ++: The number of wrinkles is 3 to 10, and the length of each wrinkle is less than 3 mm.

[0189] +: The number of folds is 3 to 10, and the length of each fold is 3 mm or more and less than 5 mm. (Practical level)

[0190] NG: The number of folds is 11 or more, or the length of each fold is 5 mm or more.

[0191] G-3. Tearing

[0192] The number of tears present in the electronic component coating layer on the electronic component-mounted substrate was counted and evaluated according to the following criteria.

[0193] ++++: The number of tears is 0 to 1.

[0194] ++++: The number of tears is 2 to 5.

[0195] ++: The number of tears is 6 to 10.

[0196] +: The number of tears is 11 to 15. (Practical level)

[0197] NG: The number of tears is 16 or more.

[0198] G-4. Stacking misalignment

[0199] Regarding the area for misalignment evaluation on the test substrate, the distance from the end of the part where the electronic component coating layer protrudes the most to the end of the area for misalignment evaluation was measured, and the evaluation was performed based on the amount of misalignment according to the following criteria.

[0200] ++++: The deviation is less than 1 mm.

[0201] +++: The deviation is 1 mm or more and less than 3 mm.

[0202] ++: The deviation is 3 mm or more and less than 5 mm.

[0203] +: The deviation is 5 mm or more and less than 7 mm. (Practical level)

[0204] NG: The deviation is 7 mm or more.

[0205] G-5. Dysplasia

[0206] The laminated sheets of each example and comparative example were cut to 25 mm × 100 mm, and a polyimide film with a thickness of 75 μm ("Kapton 300H," manufactured by DU PONT-TORAY CO., LTD.) was superimposed on the electronic component coating sheet side and laminated at 80°C. Then, the obtained samples were peeled between the peel layer and the electronic component coating sheet using a tensile testing machine at a peeling speed of 50 mm / min, and the peel strength was measured. The results were evaluated according to the following criteria.

[0207] ++++: Can be peeled off at the interface between the release layer and the electronic component coating sheet, and the peeling force is 1 N / cm or less.

[0208] +++: Can be peeled off at the interface between the release layer and the electronic component coating sheet, and the peeling force is greater than 1 N / cm and less than or equal to 2 N / cm.

[0209] ++: Can be peeled off at the interface between the release layer and the electronic component coating sheet, and the peeling force is greater than 2 N / cm and less than or equal to 3 N / cm.

[0210] +: It can be peeled off at the interface between the release layer and the electronic component coating sheet, and the peel force is greater than 3 N / cm. (Practical level)

[0211] NG: Cannot be peeled off at the interface between the release layer and the electronic component coating sheet.

[0212] [Table 1]

[0213]

[0214] [Table 2]

[0215]

[0216] [Table 3]

[0217]

[0218] [Table 4]

[0219]

[0220] It was confirmed that a coated sheet with a fracture elongation of less than 800% in (i) and / or less than 500% in (ii) has a problem with tearing during processing, as shown in Comparative Examples 1, 2, and 5. On the other hand, it was confirmed that a coated sheet with a fracture elongation of more than 2000% in (i) and more than 1500% in (ii) has a problem with wrinkling during processing, as shown in Comparative Example 3. In contrast, it was confirmed that the coated sheet of the present embodiment, which satisfies all of the above-described conditions (i) to (iii), has excellent suppression of wrinkling and tearing during processing, and also has excellent lamination position misalignment and release properties.

[0221] This application claims priority based on Japanese application No. 2023-128861 filed on August 7, 2023, and incorporates all of the disclosed therein herein. Explanation of the symbols

[0222] 1: Substrate 2: Electronic Components 3: Covering layer 4: Electronic component covering sheet 5: Stage 6: Partition board 7: Heating source 8: Support base 9: Heterogeneous layer 10, 11: Electronic component mounting boards 20: Box 21: Lower space 22: Upper space 31: Insulating layer 32: Challenge Floor 41: 1st floor 42: 2nd floor 43: 3rd floor 50 ~ 52: Laminated Sheet

Claims

Claim 1 An electronic component coating sheet for forming a coating layer of an electronic component mounting substrate comprising a substrate, an electronic component mounted on the substrate, and a coating layer covering at least a portion of the electronic component and the substrate, wherein (i) the electronic component coating sheet at room temperature is introduced under a temperature of Tg to Tg + 40°C of the electronic component coating sheet, and the elongation at break measured at a tensile speed of 50 mm / min at said temperature is 800 to 2000%, (ii) the electronic component coating sheet at room temperature is introduced under a temperature of Tg to Tg + 40°C of the electronic component coating sheet, and the elongation at break measured at a tensile speed of 1000 mm / min at said temperature is 500 to 1500%, and furthermore, (iii) the puncture strength per unit film thickness at 23°C measured by a puncture test in accordance with JIS Z1707 of the electronic component coating sheet is 10 Electronic component coating sheet with a strength of ~ 200 N / mm. Claim 2 In claim 1, the electronic component coating sheet at room temperature is introduced under a temperature of Tg to Tg + 40°C of the electronic component coating sheet, and the Young's modulus E measured at a tensile speed of 50 mm / min at said temperature 50 Furthermore, the electronic component coating sheet at room temperature is introduced under a temperature of Tg to Tg + 40°C of the electronic component coating sheet, and the Young's modulus E measured at a tensile speed of 1000 mm / min at the said temperature 1000 Department's non-E 1000 / E 50 An electronic component covering sheet with a value of 0.8 or higher. Claim 3 An electronic component coating sheet according to claim 1, comprising a thermosetting resin and a curable compound, wherein the curable compound comprises a curable compound (c1) having three or more functional groups and an N atom, and a curable compound (c2) having two functional groups and not an N atom. Claim 4 A laminated sheet comprising a support layer and an electronic component covering sheet as described in claim 1. Claim 5 In paragraph 4, a laminated sheet having a release layer between the support layer and the electronic component covering sheet. Claim 6 A laminated sheet according to claim 4, wherein when the Tg of the support layer is set to Tg2 and the Tg of the electronic component coating sheet is set to Tg1, the relationship |Tg2 - Tg1| ≤ 20℃. Claim 7 An electronic component mounting substrate comprising a substrate, an electronic component mounted on the substrate, and a covering layer covering at least a portion of the electronic component and the substrate, wherein the covering layer is a layer formed using an electronic component covering sheet described in any one of claims 1 to 3. Claim 8 A method for manufacturing an electronic component mounting substrate comprising a substrate, an electronic component mounted on the substrate, and a coating layer covering at least a portion of the electronic component and the substrate, wherein the method comprises a coating process for forming the coating layer using an electronic component coating sheet described in any one of claims 1 to 3, and wherein the coating process is performed by any one of the following methods: TOM molding, vacuum molding, pressure molding, vacuum pressure molding, press molding, and injection molding. Claim 9 A method for manufacturing an electronic component mounting substrate comprising a substrate, an electronic component mounted on the substrate, and a coating layer covering at least a portion of the electronic component and the substrate, wherein the method comprises a coating process for forming the coating layer using a laminated sheet described in any one of claims 4 to 6, and a process for removing a layer other than the coating layer from the laminated sheet after the coating process, wherein the coating process is performed by any one of the following methods: TOM molding, vacuum molding, pressure molding, vacuum pressure molding, press molding, and injection molding.

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