Electronic components mounted on substrates and electronic devices

Abstract

This invention provides an electronic component mounting substrate and an electronic device. The electronic component mounting substrate has excellent adhesion and damage resistance, and is provided with an anti-peeling layer that increases the smoothness of the corners of the components after processing, and firmly covers the substrate and the electronic components on the substrate. This prevents the electronic components from being hooked onto the mounted electronic components by fingernails or other parts during the mounting process, thereby preventing the electronic components from peeling off the substrate due to external damage. The electronic component mounting substrate of this disclosure includes a substrate, electronic components, and an anti-peeling layer, wherein the anti-peeling layer satisfies (1) the rate of change X of the static friction coefficient calculated by [Equation 1] is -50% or more and 200% or less, and (2) the exponent Y calculated by [Equation 2] is 0.8 or more and 20.0 or less. [Equation 1] X=(μk 300 -μk 100 ) / μk 100 ×100[Equation 2]Y=R2 / (R1+A1).

Description

[0001] This application claims priority based on Japanese Patent Application No. 2023-202349, filed on November 30, 2023, and incorporates all of the disclosures therein into this application. Technical Field

[0002] This disclosure relates to an electronic component mounting substrate and an electronic device. Background Technology

[0003] Electronic devices, such as smartphones and wearable devices, are used in a wide variety of environments, thus requiring high reliability to prevent malfunctions even under harsh conditions. Consequently, the miniaturization and thinning of electronic devices have led to a reduction in the size of the substrates on which electronic components are mounted, and a decrease in the contact area between the substrate and the electronic components. This, in turn, reduces the tightness of the connection between the electronic components and the substrate, increasing the likelihood of electronic components peeling off from the substrate. Therefore, the necessity to prevent breakage or slippage of electronic components in terms of physical damage, heat, and humidity has increased.

[0004] Therefore, there is a known method that protects electronic components from external damage by filling them with resin layers, such as integrated circuit (IC) chips or multilayer ceramic capacitors (MLCCs) (Patent Document 1).

[0005] However, from the perspective of thinning or cost reduction of substrates for electronic components, there is a need to form a thinner protective layer that suppresses the thickness after processing.

[0006] Existing technical documents

[0007] Patent documents

[0008] Patent Document 1: Japanese Patent Application Publication No. 2021-004314 Summary of the Invention

[0009] The problem that the invention aims to solve

[0010] As described above, inventions related to coated and protected electronic component mounting substrates have been disclosed. However, if the protective layer is made into a thin film, many problems as described below may arise. Therefore, it is desirable to have an electronic component mounting substrate that can solve these problems in one go.

[0011] The assembly of electronic devices involves several steps, including mounting various electronic components onto a substrate using solder or adhesive. After the electronic components are mounted on the substrate, steps such as assembly into the electronic device or reliability testing are performed. However, during these processes, electronic components can sometimes peel off from the substrate or shift position due to snagging by a person's fingernail or other objects. In recent years, the miniaturization and thinning of electronic components, such as multilayer ceramic capacitors (MLCCs), have rapidly advanced, resulting in a smaller contact area with the substrate. This reduces the tightness of the connection between the component and the substrate, further increasing the importance of preventing the electronic components from peeling off.

[0012] Furthermore, there is a requirement for a protective component with abrasion resistance or damage resistance that can withstand contact or friction between hard components such as metal and electronic parts. Moreover, there is a requirement for a highly reliable electronic part mounting substrate that will not peel off even after prolonged use in high-temperature and high-humidity environments.

[0013] The present invention addresses the issue of providing a highly reliable electronic component mounting substrate that exhibits excellent wear resistance and damage resistance even in miniaturized and thin electronic component mounting substrates, prevents electronic components from falling off due to external damage, and enables long-term use under high temperature and high humidity conditions.

[0014] Problem-solving methods

[0015] Through diligent research, the authors discovered that the aforementioned problem was solved by using an article (electronic component mounting substrate, anti-peeling layer, and anti-peeling sheet) having the following characteristics, thus completing this disclosure. Specifically, this disclosure relates to an electronic component mounting substrate, anti-peeling layer, and anti-peeling sheet characterized by the following:

[0016] [1]: An electronic component mounting substrate, characterized in that it comprises: a substrate; an electronic component mounted on at least one side of the substrate; and an anti-peeling layer covering the substrate and the electronic component, wherein the anti-peeling layer satisfies all of the following (1) and (2).

[0017] (1) The rate of change X of the static friction coefficient obtained by the following [Equation 1] is greater than -50% and less than 200%.

[0018] X=(μk 300 -μk 100 ) / μk 100 ×100 [Formula 1]

[0019] (μk 100 The static friction coefficient, μk, of the anti-stripping layer during the 100th reciprocating wear test. 300(Static friction coefficient of the anti-stripping layer at the 300th reciprocating wear test)

[0020] (2) The index Y obtained by the following [Equation 2] is above 0.8 and below 20.0.

[0021] Y = R2 / (R1 + A1) [Equation 2]

[0022] (R1; radius of curvature of the curved surface at the corner of the electronic component in the cross-section of the electronic component mounting substrate; R2; radius of curvature of the corner of the anti-peeling layer in the cross-section of the electronic component mounting substrate; A1; thickness of the corner of the anti-peeling layer in the cross-section of the electronic component mounting substrate)

[0023] [2]: As described in [1], the electronic component mounting substrate, wherein the anti-peeling layer comprises an adhesive (A) and a filler (B).

[0024] The BET (Brunauer-Emmett-Teller) specific surface area of ​​the filler (B) [m²] 2 The product of [ / g] and the content [mass%] of the filler (B) in 100% by mass of the anti-stripping layer is 0.01 [mass%·m 2 / g]~15[mass%·m 2 / g).

[0025] [3]: The electronic component mounting substrate as described in [1] or [2], wherein the thickness A2 of the anti-peeling layer is 5 μm to 300 μm.

[0026] [4]: An electronic device having an electronic component mounting substrate as described in any one of [1] to [3].

[0027] The effects of the invention

[0028] This disclosure provides an electronic component mounting substrate that can suppress the detachment of electronic components due to external damage even in miniaturized and thin electronic component mounting substrates for a long period of time, and an electronic device mounted on said electronic component mounting substrate. Attached Figure Description

[0029] Figure 1 This is a schematic cross-sectional view of the electronic component mounting substrate of this embodiment.

[0030] Figure 2 This is a schematic cross-sectional view of the electronic component mounting substrate of this embodiment, showing R1, R2, and A1 on the corner curved surface of the electronic component constituting the index Y.

[0031] Figure 3This is a diagram illustrating a portion of the manufacturing process of the electronic component mounting substrate according to this embodiment.

[0032] Figure 4 This is a schematic cross-sectional view showing an example of an electronic component mounting substrate according to this embodiment.

[0033] Figure 5 This is a diagram illustrating an evaluation method for an electronic component mounted on a substrate according to an embodiment.

[0034] Explanation of symbols

[0035] 1: Substrate

[0036] 2: Electronic components

[0037] 3: Anti-peeling layer

[0038] 4: Solder bumps

[0039] 5: Hollow section

[0040] 6: Anti-peeling sheet

[0041] 7: Cushioning material

[0042] 8: Functional Layer

[0043] 9: Ground wire

[0044] 10: Electronic components mounted on substrates

[0045] 11: Electronic component mounting substrate

[0046] 12: Electronic component mounting substrate with functional layers

[0047] 13: Ni-SUS board

[0048] 20: Heating and Pressurizing Machine

[0049] 30:0603MLCC

[0050] 100: Mounting substrate Detailed Implementation

[0051] The present disclosure is described below through embodiments of the invention, but these embodiments do not limit the invention as defined in the claims. Furthermore, not all combinations of features described in the embodiments are necessary for the solution of the invention.

[0052] Electronic component mounting substrate

[0053] like Figure 1As shown, the electronic component mounting substrate 10 of this disclosure includes a substrate 1, an electronic component 2 mounted on the substrate 1, and an anti-peeling layer 3 that protects the substrate 1 and the electronic component 2. The substrate 1 or the electronic component 2 has a region containing resin components (not shown), and the anti-peeling layer 3 coats its surface.

[0054] The substrate 1 can be any substrate capable of mounting electronic components 2 and withstanding molding processes for various applications. Electrode / wiring patterns, through holes (not shown), etc., can be arbitrarily set on the substrate 1. The substrate 1 can be a rigid substrate or a flexible substrate. Examples of substrate 1 include: a working board with conductive patterns made of copper foil or the like formed on its surface and / or inside, a mounting module substrate, a printed wiring board, and a composite substrate formed by assembly methods.

[0055] Examples of electronic components 2 include connectors, film capacitors, components molded from wafers or wires like IC chips, inductors, thermistors, MLCCs, coils, diodes, electrolytic capacitors, quartz oscillators, etc. Among these, MLCCs and IC chips are preferred as electronic components 2 in this disclosure due to their miniaturization.

[0056] When multiple electronic components 2 are mounted, their shapes and heights may be the same or different.

[0057] The size or height of electronic component 2 is not particularly limited, but given the recent trend towards miniaturization and thinning, a height of 3mm or less is preferred. The IC chip shape can be rectangular, cylindrical, coin-shaped, thin-film, etc. MLCCs are preferably the mainstream package sizes 0402 (0.4mm length, 0.2mm width) and 0603 (0.6mm length, 0.3mm width), but larger components such as 1005 or 1608 can also be used. Inductors include solenoids, dome-shaped coils, and planar coils. Thermistors include rectangular or cylindrical for surface mounting, and leaded types.

[0058] Electronic component 2 can be electrically connected to the substrate via solder bumps 4, or the substrate can be directly connected to the connection terminals extending from the electronic component. When electronic component 2 is connected to substrate 1 via solder bumps 4, such as... Figure 1 As shown, a hollow portion 5 is formed between the electronic component 2 and the substrate 1.

[0059] The anti-peeling layer 3 can protect the electronic component 2 and the substrate 1 by maintaining the hollow portion 5, or it can protect them by filling the hollow portion 5.

[0060] The anti-peeling layer 3 can be manufactured by the method described later.

[0061] An anti-peeling layer 3 is applied to the substrate 1 and the electronic components 2. Figure 1 In this process, the substrate 1 is coated from its upper surface to its side surface, and further to the entire surface or a portion of its end face. That is, a coating layer (anti-peeling layer 3) is provided that follows the stepped portion (undulation) formed by mounting the electronic component 2. The anti-peeling layer 3 uses an anti-peeling sheet as a precursor for the anti-peeling layer 3. Figure 3 The symbol 6 in the figure is used to form the anti-peeling layer 3. The method for forming the anti-peeling layer 3 from the anti-peeling sheet 6 is not limited, but preferably any one of the following: stamping, three-dimensional overlay method (TOM) forming, vacuum forming, air-forming, vacuum-air-forming, and injection forming. Among these, stamping is most preferred as the method for forming the anti-peeling layer 3 from the anti-peeling sheet 6.

[0062] exist Figure 1 The example described illustrates mounting electronic components 2 on one surface of substrate 1, but electronic components 2 can also be mounted on both sides of substrate 1 and coated on both sides of substrate 1 with an anti-peeling layer 3. As described above, in the electronic component mounting substrate of this disclosure, it is sufficient to mount electronic components 2 on at least one surface of substrate 1 and provide an anti-peeling layer 3 to cover substrate 1 and electronic components 2.

[0063] Anti-stripping layer

[0064] Next, the anti-peeling layer in this disclosure will be described in more detail. The anti-peeling layer 3 is used to prevent the two sets of electronic components disposed on the substrate 1 as described above from peeling off from the mounting substrate 1.

[0065] The anti-stripping layer 3 satisfies all of the following (1) and (2).

[0066] (1) The rate of change X of the static friction coefficient obtained by the following [Equation 1] is greater than -50% and less than 200%.

[0067] (2) The index Y obtained by the following [Equation 2] is above 0.8 and below 20.0.

[0068] Furthermore, the values ​​X and Y are calculated using [Equation 1] and [Equation 2] as shown below, and the determination of X and Y is based on the methods and conditions described in the embodiments described later.

[0069] Rate of change X of static friction coefficient

[0070] The rate of change of static friction coefficient X (hereinafter referred to as the rate of change of static friction coefficient X) obtained by the reciprocating wear test of the anti-stripping layer can be expressed by the following [Equation 1].

[0071] X=(μk 300 -μk 100 ) / μk 100 ×100 [Formula 1]

[0072] Here, μk 100 It is the static friction coefficient, μk, at the 100th reciprocating wear test of the anti-stripping layer. 300 It is the static friction coefficient at the 300th reciprocating wear test of the anti-stripping layer.

[0073] Regarding the static friction coefficient μk 100 static friction coefficient μk 300 The determination method is described in detail in the examples.

[0074] Regarding the rate of change X of the static friction coefficient, a wear testing machine was used for testing. The number of times the static friction coefficient stabilized during the measurement was compared with the number of times used as a benchmark for judging whether wear resistance exists. Therefore, the static friction coefficient μk of the 100th measurement was used. 100 The static friction coefficient μk, which serves as an indicator of wear resistance, is measured on the 300th time. 300 The rate of change of the static friction coefficient, X, is calculated and becomes an indicator of the wear resistance, confirming the maintenance of a certain static friction coefficient during continued reciprocating wear tests. Furthermore, a positive rate of change X indicates the progress of wear, with a larger value indicating lower wear resistance. A negative rate indicates less wear progress and increased sliding on the surface of the anti-stripping layer, which is considered to be affected by the exposed filler or wear particles and frictional heat from the anti-stripping layer surface during film surface stripping.

[0075] Furthermore, from the viewpoint of obtaining stable measurement values, the test performed using the abrasion testing machine is conducted on the smooth surface of the anti-peeling layer formed on the resin-containing area of ​​the electronic component or substrate. The term "resin area" refers to the portion of the surface covered by resin, such as molding resin or glass epoxy resin.

[0076] By setting the rate of change X of the static friction coefficient in this disclosure to be -50% or more and 200% or less, the wear resistance of the anti-peeling layer on the substrate on which the electronic component is mounted can be optimized. X is preferably -25% or more and 150% or less, more preferably -5% or more and 100% or less. By setting the rate of change X on the anti-peeling layer to the aforementioned range, the anti-peeling layer is less prone to scratches, and its wear resistance and damage resistance are improved.

[0077] [Control methods]

[0078] The method for controlling the rate of change X of the static friction coefficient of the anti-peeling layer can be any method, including those previously known. Examples include: methods that increase the surface hardness of the anti-peeling layer by adjusting the formulation added to it, thereby improving its friction resistance; methods that improve the smoothness of the oiled surface by adding wax components to the anti-peeling layer; methods that reduce surface roughness (reduction of surface friction coefficient) by reducing or changing the shape of added particulate components; methods that improve the heat resistance of the anti-peeling layer; and methods that reduce surface roughness based on the type of protective film used when forming an anti-peeling sheet as a precursor on an electronic component mounting substrate. The method for controlling the wear resistance of the anti-peeling layer surface is not limited to the illustrated methods, but any method that increases the hardening dosage in the anti-peeling layer to harden the surface, or adjusts the amount and shape of particulate matter in the anti-peeling layer to reduce surface roughness, does not require special pre-treatment / post-treatment and is therefore preferred from a production point of view.

[0079] Index Y

[0080] The exponent Y of the anti-peeling layer in this disclosure, calculated by the following [Equation 2], is 0.8 or more and 20.0 or less. By setting it to the aforementioned numerical range, a suitable shape can be obtained that smoothly covers the surface of the electronic component mounting substrate and prevents the electronic component from peeling off.

[0081] From the viewpoint of ensuring the uniformity of the anti-peeling layer thickness (followability of the part) or the thickness of the corner of the electronic part, Y is preferably 0.9 or more and 12.0 or less, more preferably 1.0 or more and 5.0 or less.

[0082] Y = R2 / (R1 + A1) [Equation 2]

[0083] Furthermore, R2, R1, and A1 in [Equation 2] are based on... Figure 2 The measured values ​​of the cross-section when the electronic component mounting substrate 11 is taken perpendicularly to the substrate surface are obtained. The radius of curvature of the curved surface at the corner of the electronic component 2 in the cross-section of the electronic component mounting substrate 11 is set as R1, the radius of curvature of the corner of the anti-peeling layer 3 in the cross-section of the electronic component mounting substrate 11 on which it is mounted is set as R2, and the corner thickness of the anti-peeling layer 3 in the cross-section of the electronic component mounting substrate 11 is set as A1 (hereinafter, the corner thickness A1 of the anti-peeling layer).

[0084] Regarding the cross-section of the electronic component mounting substrate 11, the cross-section can be cut open by cutting or grinding, and R2, R1, and A1 can be determined by measuring the length of the cross-section using, for example, a digital microscope VHX-7000 (manufactured by KEYENCE).

[0085] Furthermore, the radii of curvature R1 and R2 represent the locations where snagging is most likely to occur at each corner, and therefore refer to the radii of curvature that are at their minimum values ​​when measured at each corner.

[0086] The index Y is a value representing the change in smoothness between the corner of the electronic component 2 and the corner of the anti-peeling layer 3 on the electronic component. By setting the index Y to the range mentioned above, it is possible to prevent the electronic component 2 from peeling off due to hooking with nails or other parts, which may occur during the inspection of the electronic component mounting substrate 11 or when the electronic component mounting substrate 11 is mounted on the electronic device in a subsequent step.

[0087] The index Y can be controlled by adjusting the conformability and flowability of the anti-peeling sheet 6 to the electronic component 2 during processing. Specifically, the following methods can be used: adjusting the selection of the adhesive (A) and filler (B) constituting the anti-peeling sheet 6 (described later); adjusting the processing conditions (processing temperature, processing time, pressure conditions, vacuum degree, etc.) during the processing of the anti-peeling sheet 6 to adjust the conformability of the anti-peeling sheet 6 to the substrate 1 and the electronic component 2; and controlling the flowability of the anti-peeling sheet 6 by changing the lamination structure during processing. When using multiple anti-peeling sheets 6, different methods can be applied to each, or a common method can be applied.

[0088] Adhesive (A)

[0089] The anti-peeling layer 3 includes an adhesive (A). The adhesive (A) serves as the matrix of the anti-peeling layer and functions to support the filler (B) or other arbitrary components described later. The adhesive (A) may be any one of thermoplastic resin, thermosetting resin, or curing compound.

[0090] [Thermoplastic resin]

[0091] Examples of 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. There are no particular limitations, but from the viewpoint of heat resistance, polyamide resins, polyurethane resins, polyester resins, polycarbonate resins, polyimide resins, liquid crystal polymers, and fluoropolymers are more preferred.

[0092] Thermoplastic resins can be used alone or in combination of two or more.

[0093] [Thermosetting resin]

[0094] Thermosetting resins are resins possessing multiple functional groups capable of reacting with curing compounds. Examples of functional groups include: hydroxyl, phenolic hydroxyl, acid anhydride, methoxymethyl, carboxyl, amino, epoxy, oxacyclobutyl, oxazoline, oxazinyl, aziridinyl, thiol, isocyanate, block-modified isocyanate, block-modified carboxyl, silanol, etc. Examples of thermosetting resins include: acrylic resins, maleic acid resins, polybutadiene resins, polyester resins, polyurethane resins, polyurethane urea resins, epoxy resins, oxacyclobutane resins, phenoxy resins, polyimide resins, polyamide resins, polyamide-imide resins, phenolic resins, alkyd resins, amino resins, polylactic acid resins, oxazoline resins, benzoxazine resins, silicone resins, fluoropolymers, and other known resins.

[0095] Thermosetting resins can be used alone or in combination of two or more.

[0096] Among these, in terms of heat resistance, polyurethane resin, polyurethane urea resin, polyester resin, epoxy resin, phenoxy resin, polyimide resin, polyamide resin, and polyamide-imide resin are preferred as thermosetting resins.

[0097] [Curing compounds]

[0098] Curable compounds possess multiple functional groups capable of reacting with the functional groups of thermosetting resins. Examples of curable compounds include: epoxy compounds, compounds containing acid anhydride groups, isocyanate compounds, aziridine compounds, amine compounds, phenolic compounds, organometallic compounds, and other known compounds.

[0099] Hardening compounds can be used alone or in combination of two or more.

[0100] The curing compound is preferably a compound with two or more functions, and more preferably a compound with three or more functions. From the viewpoint of adjusting the crosslinking density to achieve both the processability of the electronic component mounting substrate as described later and the long-term stability of the composition as a precursor for the anti-peeling sheet, it is ideal to use a curing compound with two functions and a curing compound with three or more functions.

[0101] By adjusting the content of the curing compound as described below, a strong cross-linked structure is formed on the anti-peeling layer, improving the adhesion between the anti-peeling layer and the substrate, thereby enhancing reliability. Thus, the adhesion between the anti-peeling layer and the substrate can also be adjusted by the content of the curing compound in the composition.

[0102] The preferred amount of the difunctional curable compound is 1 to 50 parts by mass relative to 100 parts by mass of the thermosetting resin, and more preferably 15 to 30 parts by mass. By using 1 part or more of the difunctional curable compound, a stronger cross-linked structure is formed on the anti-stripping layer, thereby further improving resistance to heat damage. Furthermore, by using 15 parts or more of the difunctional curable compound, the surface hardness or strength of the anti-stripping layer can be adjusted, thereby further improving wear resistance. On the other hand, by using 50 parts or less of the curable compound, over-curing of the anti-stripping layer is easily suppressed, thereby easily suppressing cracking caused by shrinkage after the anti-stripping sheet has cured.

[0103] Relative to 100 parts by weight of the thermosetting resin, the curing compound with three or more functionalities is preferably contained in an amount of 0.2 to 20 parts by weight, more preferably 0.3 to 5 parts by weight, and even more preferably 0.8 to 3 parts by weight. By making the amount of the curing compound with three or more functionalities 0.2 parts by weight or more, the adhesion between the anti-peeling layer and the substrate can be further improved, thereby further improving reliability.

[0104] Furthermore, by using a curing compound with 3 or more functions at a mass of 20 parts or less, the anti-peeling sheet 6 can easily deform to follow the shape of the electronic component 2 during the heating and pressurization process in the manufacturing step of the electronic component mounting substrate described later, thereby easily forming a defect-free anti-peeling layer.

[0105] [Lubricant]

[0106] The anti-stripping layer 3 may also contain lubricants such as waxes. By adding these, the smoothness of the anti-stripping layer surface increases, thereby easily improving wear resistance. Since the anti-stripping layer surface is less prone to cracking, further improvements in reliability can be expected. Examples of waxes include: beeswax, lanolin wax, whale wax, candelilla wax, carnauba wax, rice bran wax, wood wax, jojoba oil, palm oil, and other plant and animal waxes; lignite wax, ozokerite, pure ozokerite, paraffin wax, microcrystalline wax, petrolatum, and other mineral waxes; petroleum-based waxes; Fischer-Tropsch wax, polyethylene wax, oxidized polyethylene wax, oxidized polypropylene wax, lignite wax derivatives, paraffin wax derivatives, microcrystalline wax derivatives, Teflon (registered trademark) wax, and other synthetic waxes.

[0107] Packing (B)

[0108] The anti-stripping layer 3 includes filler (B). By appropriately changing the type, average particle size, and amount of filler (B), the rate of change of the index Y and the static friction coefficient X can be controlled. In addition, the cohesion in the anti-stripping layer 3 can be adjusted so that mechanical properties such as the maximum point stress T are within a favorable range.

[0109] 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 sheet-like, needle-like, spherical, dendritic, and fibrous fillers. Fillers of different shapes can also be used in combination. As a preferred example, combinations of different spherical fillers with an average particle size of more than 10 times or more, or combinations of sheet-like fillers and dendritic fillers, can be cited.

[0110] Insulating fillers include, for example, non-metallic inorganic fillers such as silica, alumina, boron nitride, aluminum nitride, magnesium silicon nitride, silicon carbide, titanium dioxide, glass, and ceramics. Insulating fillers can be used alone or in combination of two or more.

[0111] Conductive fillers can be exemplified as metallic fillers, conductive ceramic fillers, and mixtures thereof. Metallic fillers can be exemplified as metal powders such as gold, silver, copper, and nickel; alloy powders such as solder; silver-coated copper powder; gold-coated copper powder; silver-coated nickel powder; and core-shell fillers containing gold-coated nickel powder. From the viewpoint of obtaining excellent conductivity, conductive fillers containing silver are preferred. From the viewpoint of cost, silver-coated copper powder is most preferred.

[0112] Examples of electromagnetic wave absorbing fillers include: iron, Fe-Ni alloys, Fe-Co alloys, Fe-Cr alloys, Fe-Si alloys, Fe-Al alloys, Fe-Cr-Si alloys, Fe-Cr-Al alloys, Fe-Si-Al alloys, and other ferroalloys; Mg-Zn ferrites, Mn-Zn ferrites, Mn-Mg ferrites, Cu-Zn ferrites, Mg-Mn-Sr ferrites, Ni-Zn ferrites, and other ferrite-oxygen system materials; and carbon fillers. Examples of carbon fillers include acetylene black, Ketjen black, furnace black, carbon black, carbon fibers, carbon nanotubes, graphene fillers, graphite fillers, and carbon nanowalls.

[0113] The average particle size of filler (B) is preferably 0.005 μm to 50 μm. From the viewpoint of maintaining the smoothness of the anti-stripping layer surface, reducing the influence of wear powder during wear, and improving wear resistance, the average particle size of filler (B) is more preferably 0.02 μm to 20 μm.

[0114] The filler (B) content in 100% by mass of the anti-stripping layer is preferably 0.1% to 80% by mass, and more preferably 1.0% to 35% by mass from the viewpoint of improving surface properties and thus enhancing damage resistance while suppressing the filler (B) from detaching from the surface of the anti-stripping layer. When the filler (B) content is 80% by mass or less, the wear resistance is further optimized.

[0115] The BET specific surface area [m²] of the filler (B) in the anti-stripping layer 2 The product of the specific surface area and the content of filler (B) in 100% by mass of the anti-stripping layer (hereinafter, the product of specific surface area and content) is preferably 0.01 to 15, more preferably 0.1 to 10. When using two or more fillers (B), the product of specific surface area and content is set as the sum of the products of specific surface area and content required for each filler (B) contained in the anti-stripping layer.

[0116] If the product of specific surface area and content is within the range described above, the filler (B) functions as a reinforcing material in the anti-peeling sheet. Therefore, in the manufacturing steps of the electronic component mounting substrate described later, the breakage of the anti-peeling sheet 6 can be easily prevented during heating and pressurization, thereby easily forming a defect-free anti-peeling layer.

[0117] Furthermore, when the product of specific surface area and content is less than 15, damage resistance and anti-peeling properties can be easily optimized by further ensuring the adhesion between the anti-peeling layer and the substrate and electronic components.

[0118] BET specific surface area of ​​filler (B) [m 2 The preferred value is 0.1 to 150 g.

[0119] The anti-peeling sheet 6 may also contain a softening agent. The softening agent can easily improve wrinkles or cracks during the molding process of the anti-peeling sheet 6. Examples of softening agents include plasticizers and inert thermoplastic resins that are scientifically non-reactive.

[0120] Examples of plasticizers include fatty acid esters, phthalates, aromatic polycarboxylic acid esters, and polyesters.

[0121] Examples of fatty acid esters include: Trioctyl trimellitate (TOTM), manufactured by Mitsubishi Gas Chemical Trading Co., Ltd.; Butyl stearate; Unistar M-9676; Unistar M-2222SL; Unistar H-476; Unistar H-476D; Panasate 800B; Panasate 875; Panasate 810 (trade names, manufactured by Nippon Oil Manufacturing Co., Ltd.); DBA; DIBA; DBS; DOA; DINA; DIDA; DOS; BXA; DOZ; DESU (trade names, manufactured by Daihachi Chemical Co., Ltd.).

[0122] Examples of phthalates include: DMP, DEP, DBP, #10, BBP, DOP, DINP, DIDP (trade names, manufactured by Daihachi Chemical), PL-200, DOIP (trade names, manufactured by CG Ester), and Sansocizer DUP (trade name, manufactured by Shin Nippon Rikka).

[0123] Examples of aromatic polycarboxylic acid esters include: TOTM (trade name, manufactured by Daihachi Chemical), Monocizer W-705 (trade name, manufactured by Daihachi Chemical), UL-80, and UL-100 (trade names, manufactured by ADEKA).

[0124] Examples of polyesters include: Polycizer TD-1720, Polycizer S-2002, Polycizer S-2010 (trade names, manufactured by DIC), and BAA-15 (trade name, manufactured by Daihachi Chemical).

[0125] Among these, DMP, DEP, DBP, DOP, DINP, DIDP, and TOTM (these are trade names) are preferred. A single plasticizer may be used, or two or more may be used in combination.

[0126] Examples of inert 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. There are no particular limitations, but from the viewpoint of heat resistance, polyamide resins, polyurethane resins, polyester resins, polycarbonate resins, polyimide resins, liquid crystal polymers, and fluoropolymers are more preferred as inert thermoplastic resins.

[0127] Furthermore, to improve adhesion to the substrate 1 and electronic components 2, the anti-peeling sheet 6 may also include an adhesion-enhancing resin. An adhesion-enhancing resin is a component that auxiliaryly improves adhesion and has a weight average molecular weight of less than 5,000, distinguishing it from the aforementioned thermoplastic resins and adhesives. Examples of adhesion-enhancing resins include rosin-based resins, terpene-based resins, alicyclic petroleum resins, and aromatic petroleum resins.

[0128] The anti-peeling sheet 6 may also contain colorants, ultraviolet (UV) colorants, flame retardants, lubricants, anti-blocking agents, etc.

[0129] Examples of colorants include: organic pigments, carbon black, cyan, red lead, zinc white, titanium dioxide, lead black, and dyes.

[0130] Examples of UV color developers include fluorescent pigments, fluorescent dyes, and phosphors.

[0131] Examples of flame retardants include halogenated flame retardants, phosphorus-containing flame retardants, nitrogen-containing flame retardants, and inorganic flame retardants.

[0132] Examples of lubricants include: fatty acid esters, hydrocarbon resins, paraffin wax, higher fatty acids, fatty acid amides, aliphatic alcohols, metal soaps, and modified silicones.

[0133] Examples of anti-blocking agents include calcium carbonate, silica, polymethylsilsesquioxane, and aluminum silicates.

[0134] Alternatively, one or more of these additives may be used.

[0135] Thickness of the anti-stripping layer A2

[0136] The thickness A2 of the anti-peeling layer 3 is 5 μm to 300 μm, but from the viewpoint of achieving both anti-peeling properties (wear resistance, damage resistance) and thin-film properties for the electronic component 2, 15 μm to 200 μm is more preferable. Furthermore, as... Figure 2As shown, the thickness A2 is the measured value of a certain part with the highest thickness formed on the upper surface region of the electronic component 2 in the cross-sectional image of the electronic component 2.

[0137] Maximum point stress T of the anti-stripping layer

[0138] The maximum point stress T of the anti-peeling layer 3 is a value obtained through a tensile test according to Japanese Industrial Standards (JIS) K 7162. Specifically, it is the maximum stress T when the anti-peeling layer with an effective tensile dimension of 20mm × 23mm is stretched at 50mm / min in an environment of 100°C (atmosphere, 50% RH).

[0139] The maximum point stress T is preferably 1 MPa or more and 100 MPa or less, more preferably 15 MPa or more and 40 MPa or less.

[0140] When the maximum point stress T is 1 MPa or higher, wear resistance or damage resistance can be further improved. On the other hand, when the maximum point stress T is 100 MPa or lower, the following of the anti-peeling sheet 6 to the electronic component 2 is further improved when forming the anti-peeling layer onto the electronic component. Furthermore, it is easy to suppress defects in appearance and processing such as gaps between the anti-peeling layer 3 and the substrate 1 or between the anti-peeling layer 3 and the electronic component 2, or peeling of the electronic component 2 or breakage of the anti-peeling layer 3 at the corner due to easy cracking or fissures in the anti-peeling layer 3.

[0141] The maximum point stress T of the anti-peeling layer 3 can be adjusted, for example, by selecting the thermoplastic or thermosetting resin, the crosslinking density in the anti-peeling layer, and the filler. Regarding the crosslinking density, it is preferable to adjust the functional groups and equivalents of the curing compounds in the composition used to form the anti-peeling layer. Regarding the selection of fillers, factors such as the filler's material or shape, size, surface condition, specific surface area, and amount added can be considered, but it is preferable to take into account the filler's specific surface area and the amount added.

[0142] Tg of the anti-stripping layer

[0143] The Tg of the anti-stripping layer 3 is a value measured using a dynamic viscoelasticity measuring device. When the Tg of multiple anti-stripping layers can be confirmed, the value representing the highest tanδ is selected. The Tg of the anti-stripping layer 3 is preferably 5°C or higher and 180°C or lower, more preferably 20°C or higher and 80°C or lower. By setting the Tg to 5°C or higher and 180°C or lower and adjusting the flowability of the anti-stripping layer, the anti-stripping layer can be easily processed into an optimal shape, thereby easily bringing the index Y within the optimal range. Furthermore, by setting the Tg to 20°C or higher and 80°C or lower, resistance to frictional heat caused by wear or thermal damage during subsequent inspections can be easily achieved, thereby further improving reliability.

[0144] When the adhesive (A) contains a thermosetting resin, the maximum point stress T and Tg refer to the material after it has been heated and hardened.

[0145] Anti-peeling sheet

[0146] like Figure 3 As shown, the anti-peeling sheet 6 is a precursor to the anti-peeling layer 3. When the anti-peeling sheet 6 contains a thermosetting resin, it undergoes a curing reaction by heating the anti-peeling sheet 6 for a specified time and temperature, thus becoming the anti-peeling layer 3. For surface protection, the anti-peeling sheet 6 may also include a peelable sheet on one or both sides. Additionally, the cushioning material 7 used in the coating protection step using the anti-peeling sheet 6, described later, may be pre-laminated.

[0147] Manufacturing Method of Anti-peeling Sheets

[0148] The manufacturing method of the anti-peeling sheet 6 is not particularly limited. For example, a method of coating a composition formed by dissolving the adhesive (A) or other materials that form the anti-peeling layer 3 in a solvent or the like onto the peelable sheet can be included. As for the coating method, examples include gravure coating, coincidence coating, die coating, lip coating, corner wheel coating, squeegee coating, roller coating, doctor blade coating, spray coating, bar coating, spin coating, dip coating, or various printing methods.

[0149] To achieve the desired thickness, the anti-peeling sheet 6 of this disclosure can be laminated with two or more anti-peeling sheets. For the laminated structure as described above, it may consist of only anti-peeling sheets, or it may include layers with specific functions as intermediate layers.

[0150] Applications of anti-peeling sheets

[0151] The anti-peeling sheet 6 in this disclosure can preferably be used for the protection of various substrates 1, such as rigid substrates, flexible printed circuit (FPC) substrates, and electronic components 2 mounted thereon.

[0152] Furthermore, the anti-peeling sheet 6 of this disclosure exhibits sufficient adhesion in practical applications when the substrate 1 is any one of metal, resin, fiber, ceramic, glass, and conductive silicone. As a metal, aluminum, copper, brass, stainless steel, iron, chromium, etc., can be used. As a resin, epoxy resin, polyethylene terephthalate, polyimide, polyamide, polyethylene, polypropylene, polyolefin graft polymers, polystyrene, polyvinyl chloride, etc., can be used. Thus, the anti-peeling sheet 6 can also be preferably used for bonding dissimilar materials with different polarities.

[0153] Manufacturing Method of Electronic Component Mounting Substrate

[0154] The manufacturing method of the substrate for mounting electronic components is described.

[0155] The method for manufacturing the electronic component mounting substrate disclosed herein can be achieved through the following steps: mounting one or more electronic components 2 on a substrate 1 (step i); preparing an anti-peeling sheet 6 (step ii); placing the anti-peeling sheet 6 such that the tallest electronic component 2 is in contact with the anti-peeling sheet 6 (step iii, also known as a temporary stretching step); deforming the anti-peeling sheet 6 by heating and pressurizing it to conform to the shape of each electronic component 2 and covering at least a portion of the electronic component 2 and the substrate 1 (step iv); and hardening the deformed anti-peeling sheet 6 in a deformed state to form an anti-peeling layer 3 (step v). The electronic component mounting substrate is thus protected by the anti-peeling layer 3 formed from the anti-peeling sheet 6 of this disclosure. Furthermore, steps iv and v can also be a series of steps.

[0156] The following describes steps iii to v. Figure 3 An example of a method for protecting an electronic component mounting substrate by heating and pressurizing an anti-peeling sheet 6 will be described.

[0157] (Step iii: Anti-peeling sheet placement step)

[0158] A mounting substrate 100 is prepared to mount electronic components 2 directly on a substrate 1 or via solder bumps 4. The electronic components 2 are semiconductor chips, capacitors, transistors, inductors, thermistors, etc., and can be mounted to the substrate 1 via solder bumps 4, or a gap may exist between the electronic components 2 and the substrate 1. Furthermore, the height of each electronic component 2 may vary.

[0159] Subsequently, a peel-resistant sheet 6 cut to a specified size is placed on the mounting surface of the electronic component 2. The peel-resistant sheet 6 is temporarily adhered to a component having the height of the electronic component 2. Furthermore, the peel-resistant sheet 6 is sometimes bent and made to contact other electronic components 2 (in... Figure 3 (Not shown in the image).

[0160] Furthermore, a cushioning material 7 can also be laminated on the anti-peeling sheet 6. Figure 3 This illustrates an example using cushioning material 7. Cushioning material 7 can be laminated after the anti-peeling sheet 6 is placed, or it can be a laminate obtained by pre-overlapping the anti-peeling sheet 6 and cushioning material 7. The cushioning material 7 refers to a material that softens or melts under heat and pressure, and has the function of promoting the conformity of the anti-peeling sheet 6 to the electronic component 2 and to the conformity of the gaps between the electronic components 2.

[0161] The buffer material 7 is not particularly limited to any thermoplastic material, but preferably has a melting temperature and glass transition point (Tg) lower than the temperature at which pressure is applied. Preferred examples of the buffer material 7 include polyolefin films, vinyl chloride films, and polyvinyl alcohol (PVA) films. Although the thickness depends on the depth of the groove, the thickness of the buffer material 7 is typically around 100 μm to 1 mm. When multiple buffer materials 7 are laminated, their total thickness is preferably within the aforementioned range.

[0162] Furthermore, the electronic component mounting substrate disclosed herein is just one example. The structure of the electronic component and the substrate is not particularly limited, and there may or may not be a gap between the electronic component 2 and the substrate 1. The placement position of the mounted electronic component 2 is not limited.

[0163] (Step iv: Coating at least a portion of the electronic components and substrate)

[0164] Subsequently, the anti-peeling sheet 6 is deformed by heating and pressurizing using a heating press 20, in a manner that follows the shape of each electronic component 2, that is, along the upper surface and side surface of the electronic component 2, to follow at least a portion of the electronic component assembly and the substrate 1. The buffer material 7 softens or melts due to heat, promoting the anti-peeling sheet 6 to follow the unevenness between the electronic components of the mounting substrate 100.

[0165] A preferred method is to sandwich a release sheet (not shown) between the heating and pressurizing machine 20 and the buffer material 7 during heating and pressurization. The release sheet is a sheet obtained by performing a known peeling process on a substrate such as paper or plastic. Alternatively, a low-polarity plastic sheet such as Teflon (registered trademark) can also be used.

[0166] The heating temperature is sufficient to moderately soften the anti-peeling sheet 6, deform it along the shape of each electronic component 2, and allow it to penetrate into the gaps between the electronic components. Preferably, it is between 100°C and 260°C, more preferably between 120°C and 240°C. If the heating temperature is above 100°C, it is easier to prevent a decrease in the penetration of the anti-peeling sheet 6 into the gaps between the mounted electronic components. On the other hand, if the heating temperature is below 260°C, the thermosetting reaction of the thermosetting resin of the anti-peeling sheet 6 proceeds rapidly, thereby easily preventing a decrease in the penetration of the anti-peeling sheet into the mounted electronic components.

[0167] The pressure during heating and pressurization is preferably 0.01 MPa to 15 MPa, more preferably 0.1 MPa to 6.0 MPa. By heating and pressurizing at pressures within the aforementioned range, embeddability is further improved without damaging the electronic components.

[0168] The heating time is typically from 0.5 minutes to 30 minutes, preferably from 1 minute to 20 minutes. A heating time of 0.5 minutes or more helps prevent reduced accessibility between electronic components mounted on the anti-peeling sheet in all six directions. Conversely, a heating time of 30 minutes or less helps prevent the thermal decomposition or oxidation of the thermosetting resin, increasing the likelihood of reduced reliability at the bonding surfaces due to reaction products. The heating and pressurizing step is preferably performed under vacuum.

[0169] As a method of heating and pressurizing, in addition to using a heating and pressurizing machine, it is also preferable to laminate a metal plate of appropriate weight in a manner that reaches a specified pressure and then put the laminate into an oven.

[0170] On the other hand, vacuum forming or vacuum air forming is also preferred as a heating and pressurizing method other than a heating and pressurizing machine.

[0171] (Step v: Hardening steps for the deformed anti-peeling sheet)

[0172] When the anti-peeling sheet 6 contains a thermosetting resin, after heating and pressurizing, while the anti-peeling sheet 6 is deformed, it is further heated at a temperature of 150°C to 230°C for 10 to 60 minutes, thereby thermosetting the thermosetting resin in the anti-peeling sheet 6 to form the anti-peeling layer 3. The anti-peeling layer 3 is firmly bonded to the electronic component 2 and the substrate 1, and functions as an anti-peeling layer 3 to prevent and protect the electronic component 2 from damage due to external impacts or scratches. Furthermore, in the stage of (step iv), for example, by heating and pressurizing at a temperature of 150°C or higher for a time of 30 minutes or more, thermosetting can also be completed to form the anti-peeling layer 3.

[0173] The electronic component mounting substrate disclosed herein preferably has an anti-peeling layer as its outermost layer. Alternatively, other functional layers may be deposited on the inner layers. These other functional layers may include, for example, layers with properties such as conductivity, hard coating, water vapor barrier, oxygen barrier, thermal conductivity, low dielectric constant, high dielectric constant, and heat resistance. Among these, the conductive functional layer is sometimes used to protect the electronic component to be covered from electromagnetic noise.

[0174] Figure 4 The diagram shows a structural example of an electronic component mounting substrate 12 including a conductive functional layer 8 on an anti-peeling layer 3. The conductive functional layer 8 is formed on the upper side (top layer) of the anti-peeling layer 3 and is connected to a ground line 9. The connection point to the ground line 9 may be located on the surface of the substrate 1 or on the side of the substrate 1. The conductive functional layer 8 can be formed by sputtering or plating a metal layer (not shown) on the surface of the anti-peeling layer 3, or by depositing a conductive metal foil or non-woven fabric, etc., on the anti-peeling layer 3.

[0175] Electronic Equipment

[0176] The electronic component mounting substrate disclosed herein is preferably included not only in liquid crystal displays, touch panels, etc., but also in electronic devices such as laptops, mobile phones, smartphones, and tablet terminals.

[0177] Example

[0178] The present disclosure is described in detail below with examples and comparative examples, but the present disclosure is not limited to the following examples. Furthermore, unless otherwise specified, the term "parts" below refers to values ​​based on "parts by mass".

[0179] "raw material"

[0180] The following shows the raw materials used in the examples.

[0181] <Thermosetting Resins>

[0182] Thermosetting resin (r1): Polyurethane resin (molecular weight (Mw) = 130,000, acid value 10 mg KOH / g, Tg = 20℃), manufactured by Toyo Chemical Co., Ltd.

[0183] Thermosetting resin (r2): Polyurethane resin (molecular weight (Mw) = 125000, acid value 10 mg KOH / g, Tg = -6℃), manufactured by Toyo Chemical Co., Ltd.

[0184] Thermosetting resin (r3): Acrylic resin (molecular weight (Mw) = 55000, acid value 7 mg KOH / g, Tg = -20℃), manufactured by Toyo Chemical Co., Ltd.

[0185] <Calming Compounds>

[0186] Curing compound (c1): 4-functional epoxy resin "TETRAD-X" (epoxy equivalent = 100 g / eq), manufactured by Mitsubishi Chemical Corporation.

[0187] Curing compound (c2): Difunctional epoxy resin "jER828" (epoxy equivalent = 189 g / eq), manufactured by Mitsubishi Chemical Corporation.

[0188] Curing compound (c3): Difunctional epoxy resin "AER9000" (epoxy equivalent = 380 g / eq), manufactured by Asahi Kasei E-materials Co., Ltd.

[0189] <Lubricant>

[0190] Lubricant (L1): Carnauba wax "CERACOL 79" (20% by weight of non-volatile components), manufactured by BYK.

[0191] <Packaging (B)>

[0192] Filler F1: Carbon black "MA100" (trade name, average primary particle size: 24nm, BET specific surface area: 120m²) 2 / g), manufactured by Mitsubishi Chemical Corporation

[0193] Filler f2: Silica "UltraSil U360" (trade name, average primary particle size: 28nm, BET specific surface area: 50m²) 2 / g) Manufactured by Nanocyl

[0194] Filler f3: Silica "ADMAFINE SO-C5" (trade name, average primary particle size: 2.0 μm, BET specific surface area: 2.1 m²) 2 / g), manufactured by ADMATECHS.

[0195] Packing material f4: Plate-shaped boron nitride "HP-1" (trade name, average primary particle size: 9.0 μm, BET specific surface area: 3.1 m²) 2 / g), manufactured by JFE MINERAL.

[0196] Filler F5: Silica "EXCELICA SE-30K" (trade name, average primary particle size: 25.1 μm, BET specific surface area: 0.7 m²) 2 / g) Manufactured by Tokuyama Corporation

[0197] Filler f6: Flake silver powder "FA-S-18" (trade name, average primary particle size: 3.1 μm, BET specific surface area: 2.0 m²) 2 / g), manufactured by Dow Chemical Company

[0198] Filler f7: Dendritic silver-coated copper powder "ACAX-225M" (trade name, average primary particle size: 7.4μm, BET specific surface area: 0.86m²). 2 / g), manufactured by Mitsui Metals & Mining Co., Ltd.

[0199] Determination Method

[0200] < Rate of change X of static friction coefficient during reciprocating wear test>

[0201] For the anti-peeling layers of each embodiment and comparative example, a chip (electronic component) made of molding resin (sealing resin) or a smooth portion of 6mm × 6mm or larger on the substrate of the electronic component mounted in the resin-containing area below the anti-peeling layer was used as a test specimen for measurement. A HEIDON TRIBOGEAR (TYPE: 22H) continuous-weight surface property measuring instrument (manufactured by Shin-Tung Science & Technology Co., Ltd.) was used. The fully dried test specimen was placed on the test bench, a load of 100g was applied to the friction component, and the static friction coefficient μk was recorded at the 100th and 300th reciprocating cycles. 100 static friction coefficient μk 300 Furthermore, a ball indenter was used in the measuring fixture for the reciprocating motion on the test specimen surface, and a stainless steel (SUS) ball (φ (diameter) 3.0 mm) was used as the friction component. The obtained static friction coefficient μk 100 static friction coefficient μk 300 The change in static friction coefficient X during the reciprocating wear test is calculated by applying [Equation 1] below.

[0202] [Equation 1] X=(μk 300 -μk 100 ) / μk 100 ×100

[0203] <Index Y>

[0204] like Figure 2As shown, the anti-peeling layer 3 and electronic component mounting substrate 12 of each embodiment and comparative example, manufactured by the method described later, were cross-sectioned by grinding. The radii of curvature R1 and R2 of the curved surfaces at the corners of the electronic components and the covered anti-peeling layer were determined using a digital microscope VHX-7000 (trade name, manufactured by KEYENCE). The thickness of the thinnest part at the corner of the anti-peeling layer (corner thickness of the anti-peeling layer) A1 was determined in the same manner. In the evaluation of these electronic components and anti-peeling layers, components with dimensions of 0.3 mm on the short side and 0.6 mm on the long side (hereinafter also referred to as 0603MLCC, 0603MLCC 30) were used. The obtained radii of curvature R1, radii of curvature R2, and corner thickness A1 of the anti-peeling layer were applied to the following [Equation 2] to calculate the exponent Y.

[0205] [Equation 2] Y = R2 / (R1 + A1)

[0206] <Thickness of the anti-stripping layer A2>

[0207] The thickness of the anti-peeling layer in the electronic component mounting substrate is defined as the film thickness at the highest point on the upper surface of the electronic component, observed by a VHX-7000 digital microscope (trade name, manufactured by Keyence) after cross-sectioning via grinding. The same measurement was performed on five different cross-sectioned samples of the electronic component mounting substrate, and the average value was taken as the thickness A2.

[0208] <Average particle size of filler (B)>

[0209] The average particle size of filler (B) is determined by averaging 20 primary particles observed in images magnified to approximately 50,000 to 1,000,000 times using a transmission electron microscope (TEM). Furthermore, when the particle shape of filler (B) has an average aspect ratio (major axis length / minor axis length) of 1.5 or higher, the average particle size is calculated by averaging the major axis length.

[0210] <Maximum point stress T of the anti-stripping layer>

[0211] The anti-peeling sheets with release films of each embodiment / comparative example were heated at 180°C for 2 hours and cut into pieces with a width of 20 mm and a length of 60 mm. Then, test specimens (anti-peeling layers) including the anti-peeling sheets were obtained by peeling off the release film. Each test specimen (anti-peeling layer) was placed at room temperature (e.g., 25°C) in an environment of 100°C (atmosphere, 50% RH (relative humidity)). After 1 minute, a tensile test was performed at this temperature using a small benchtop testing machine EZ-TEST (trade name, manufactured by Shimadzu Corporation) at a tensile speed of 50 mm / min and a relative humidity of 50%, with an effective tensile size of 20 mm × 23 mm. The maximum stress T (maximum point stress T) at a tensile speed of 50 mm / min was then determined.

[0212] <Glass transfer temperature Tg>

[0213] For the test specimens (anti-peeling layer) of each embodiment and comparative example, Tg was measured using a dynamic viscoelasticity measuring device DVA-200 (trade name, manufactured by IT Measurement & Control Co., Ltd.) according to JIS K7198. The test specimens were those where the anti-peeling layer of each example was cut into 0.5cm × 3cm pieces and the release film was removed. The deformation mode was tension, and Tg was defined as the temperature at which the main dispersion peak of the loss tangent (tanδ) appeared, measured at a strain of 0.08%, a frequency of 10Hz, and a heating rate of 10℃ / min. However, for test results where the anti-peeling layer fractured during the measurement due to brittleness, Tg could not be calculated; therefore, it was stated in the example table as "unable to measure".

[0214] Fabrication of Anti-peeling Sheets

[0215] [Example 1]

[0216] 100 parts of thermosetting resin r1 (solid component), 2.0 parts of hardener c1, 10 parts of hardener c2, 2.9 parts of filler f1, and 159 parts of filler f4 were placed in a container. A toluene:isopropanol (mass ratio 2:1) mixture was added to achieve a non-volatile component concentration of 45% by mass, and the mixture was stirred in a disperser for 10 minutes to obtain the composition. The composition was then applied to a release sheet with a dry thickness of 80 μm using a doctor blade. The sheet was then dried at 100°C for 2 minutes to obtain the anti-peeling sheet of Example 1.

[0217] [Examples 2-21, Comparative Examples 1-4]

[0218] By changing the types and quantities of materials listed in Tables 1 to 3, and otherwise performing the same procedures, anti-peeling sheets (laminated sheets) for Examples 2 to 21 and Comparative Examples 1 to 4 were obtained respectively. The evaluation results for each anti-peeling sheet are also described below.

[0219] Fabrication of substrates for electronic components

[0220] (Fabrication of mounting substrate)

[0221] A mounting substrate is prepared, on which molded and sealed electronic components (1cm × 1cm) are mounted in an array of 5 × 1 units, and 0603 MLCCs (0.6mm long, 0.3mm wide) are mounted in an array of 8 × 2 units. The substrate thickness is 0.6mm, and the molding seal thickness, i.e., the height (part height) H from the top surface of the substrate to the top surface of the molding sealant, is 0.7mm. The mounting spacing of the 0603 MLCCs is 200μm.

[0222] On the mounting substrate, the anti-peeling sheets of each embodiment and comparative example were heat-pressed together for 5 minutes at 2 MPa and 180°C, and the cushioning material was peeled off by hand. Subsequently, they were heated at 180°C for 2 hours, and electronic component mounting substrates of each embodiment and comparative example were obtained based on Tables 1 to 3.

[0223] "evaluate"

[0224] [Abrasion Resistance]

[0225] For the anti-peeling layers of each embodiment and comparative example, the anti-peeling layer on the molded and sealed electronic component in the mounting substrate was used as the test area for measurement. A continuously weighted surface quality tester (HEIDON TRIBOGEAR TYPE: 22H, trade name, manufactured by Shin-Tung Science & Technology Co., Ltd.) was used. A fully dried test specimen was mounted on the test bench, and a 100g load was applied to the friction element. After the number of reciprocating cycles according to the evaluation criteria below, the surface condition of the test specimen was observed. Then, it was confirmed whether the substrate had been exposed and the anti-peeling layer had cracked (reciprocating wear test). In cases where these evaluations were difficult to observe visually, a digital microscope (VHX-7000, trade name, manufactured by Keyence Co., Ltd.) was used to observe the surface condition at 20x magnification. Furthermore, a ball indenter was used as the measuring fixture during the reciprocating motion on the test specimen surface, and an SUS ball (φ3.0mm) was used as the friction element. Additionally, based on the results, the wear resistance was evaluated according to the following criteria.

[0226] (Evaluation Criteria)

[0227] +++: After 500 cycles, the electronic components beneath the anti-peeling layer were not exposed. (Excellent)

[0228] ++: After 400 cycles, the electronic components beneath the anti-peeling layer were not exposed, but after 500 cycles, they were exposed. (Good)

[0229] +: After 300 cycles, the electronic components beneath the anti-peeling layer were not exposed, but after 400 cycles, they were exposed. (Practical level)

[0230] NG: Electronic components beneath the anti-peeling layer are exposed at a time point when the number of round trips is less than 300 (i.e., after 300 round trips). (Defective)

[0231] [Anti-peeling properties]

[0232] like Figure 5 As shown, for the anti-peeling layer 3 on the corner of the 0603MLCC30 in the electronic component 2 on the electronic component mounting substrate manufactured by the method described above, the end of the Ni-SUS plate 13 (a component with a 2μm thick nickel layer formed on the surface of a commercially available SUS304 plate with a thickness of 0.2mm) is brought into contact at a 45° angle and ejected from the side of the corner of the 0603MLCC30 toward the top surface. This action is repeated 30 times for each location, and the number of electronic components 30 that peel off from the electronic component mounting substrate after operating on the anti-peeling layer 3 on all 16 0603MLCC30 mounted on the electronic component mounting substrate 12 is counted and evaluated as the anti-peeling performance (peeling test). Here, the 0603MLCC without the anti-peeling layer peeled off in approximately 10 tests under the same conditions.

[0233] Furthermore, the term "peeling" refers to the state in which, compared to before the test, there is a state where there is no contact between the electronic component mounting substrate and the electronic component due to damage between the electronic component mounting substrate and the electronic component or between the electronic component mounting substrate and the anti-peeling layer.

[0234] (Evaluation Criteria)

[0235] +++: The number of MLCCs peeled off is 0. (Excellent)

[0236] ++: The number of MLCCs peeled off is 1. (Good)

[0237] +: The number of MLCCs peeled off is 2 or 3. (Practical level)

[0238] NG: The number of detached MLCCs is 4 or more. (Defective)

[0239] [Damage Resistance]

[0240] Prepare a 30mm × 80mm Ni-SUS plate (a component with a 2μm thick nickel layer formed on the surface of a commercially available SUS304 plate with a thickness of 0.2mm). On this plate, the anti-peeling sheets (25mm × 70mm) of each embodiment and comparative example are hot-pressed together at 2MPa and 180°C for 5 minutes, and the cushioning material is then peeled off by hand. Subsequently, the plates are heated at 180°C for 2 hours to obtain test specimens (anti-peeling layer). For the test specimens, according to JIS K7317, a scratch test is performed using a HEIDON TRIBOGEAR (TYPE: 22H, trade name, manufactured by Shin-Tung Science & Technology Co., Ltd.) continuously weighing the vertical load at 50mm / min to measure the peeling of the anti-peeling sheet coated on the substrate. A diamond (0.25mmR) scratching needle is used as the scratching needle on the surface of the test specimen. The damage resistance is evaluated based on the load on the substrate when the test specimen is exposed, according to the following criteria.

[0241] Furthermore, the so-called scratches in the resistance to damage refer to the state in which the anti-peel layer peels off due to cracking or elongation when the front end of the scratching jig scratches the anti-peel layer, thus exposing the substrate, rather than needle marks that are easily altered by the observer.

[0242] (Evaluation Criteria)

[0243] +++: Vertical load when substrate is exposed ≥350g (Excellent)

[0244] ++: 350g > Vertical load when substrate exposed ≥ 250g. (Good)

[0245] +: 250g > Vertical load ≥ 200g when substrate is exposed. (Practical)

[0246] NG: 200g > Vertical load when substrate is exposed. (Defective)

[0247] [reliability]

[0248] A molded resin substrate (60mm × 50mm) was prepared. The anti-peeling sheets (55mm × 45mm) of each embodiment and comparative example were heat-pressed at 2MPa and 180°C for 5 minutes, and the buffer material was then peeled off by hand. Subsequently, the samples were heated at 180°C for 2 hours to obtain the test specimens (anti-peeling layer). For these test specimens, 25 checkerboard patterns with a 1mm spacing were fabricated on the anti-peeling layer of the electronic component according to JIS K5600 using a cross-cutting guide. The adhesive tape was then pressed together, and the ends of the tape were peeled off at a 45° angle to perform a cross-cutting test. The adhesive tape used was 18mm wide Nichiban adhesive tape.

[0249] The condition (cross-sectional retention rate) of the anti-peeling layer remaining on the molding resin substrate in the substrate grid of the anti-peeling layer is evaluated according to the following criteria.

[0250] (Evaluation Criteria)

[0251] +++: Shows a 100 / 100 cross-cutting survival rate. (Extremely good)

[0252] ++: Shows a cross-sectional survival rate of 95-99 / 100. (Good)

[0253] +: Indicates a cross-sectional survival rate of 80-94 / 100. (Practical)

[0254] NG: A cross-sectional survival rate of less than 80 / 100. (Poor)

[0255] The content, thickness Ta, and protective film were changed to those shown in Tables 1 to 3. Otherwise, the sealing sheet was prepared using the same method as in Example 1, and the evaluation was performed in the same manner. Furthermore, any crosslinking agent, oligomer, monomer, polymerization initiator, or other components were added simultaneously.

[0256]

[0257]

[0258]

[0259] It can be confirmed that, as shown in Comparative Example 1 or Comparative Example 2, the anti-stripping layer with a static friction coefficient change rate X of less than -50% or more than 200% has issues with wear resistance and anti-stripping performance. It can be confirmed that, as shown in Comparative Example 3 or Comparative Example 4, the anti-stripping layer with an index Y of less than 0.8 or more than 20.0 has issues with anti-stripping performance. In contrast, it has been confirmed that the anti-stripping layer of this embodiment, which satisfies all of (1) and (2) of the first invention, also has excellent wear resistance, anti-stripping performance, damage resistance, and reliability.

Claims

1. An electronic component mounting substrate, characterized by Comprising: a substrate; an electronic component mounted on at least one surface of the substrate; and an anti-peeling layer covering the substrate and the electronic component, the anti-peeling layer satisfying all of (1) and (2); (1) a rate of change X of the static friction coefficient calculated from the following [Formula 1] is -50% or more and 200% or less; (2) an index Y calculated from the following [Formula 2] is 0.8 or more and 20.0 or less; X = (μk 300 - μk 100 ) / μk 100 x 100 [Equation 1] wherein μk 100 μk 300 is the static friction coefficient at the 300th reciprocal abrasion test of the anti-stripping layer; Y = R2 / (R1 + A1) [Formula 2] wherein R1 is a radius of curvature of a curved surface of a corner of the electronic component in a cross section of the electronic component-mounted substrate, R2 is a radius of curvature of a corner of the anti-peeling layer in the cross section of the electronic component-mounted substrate, and A1 is a corner thickness of the corner of the anti-peeling layer in the cross section of the electronic component-mounted substrate. the anti-peeling layer contains a binder (A) and a filler (B), 2. The electronic component mounting substrate according to claim 1, wherein a thickness A2 of the anti-peeling layer is 5 to 300 μm. The product of the BET specific surface area [m 2 / g] of the filler (B) and the content [mass %] of the filler (B) in 100 mass % of the peel-resistant layer 100 is 0.01 to 15 [mass %·m 2 / g].

3. The electronic component mounting substrate according to claim 1, wherein 4. An electronic device mounted with the electronic component-mounted substrate according to any one of claims 1 to 3. ​

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