JP5266461B2 - Resin for electronic board filling - Google Patents

Description

  The present invention relates to an electronic substrate filling resin. More specifically, the present invention relates to an electronic substrate filling resin suitable for filling openings (through holes, via holes, etc.) provided on a substrate such as a printed wiring board or a silicone wafer.

  As an electronic substrate filling resin, the value of the storage elastic modulus (G ′) is equal to or higher than the value of the loss elastic modulus (G ″) at any frequency of 10 to 100 rad / s {tan δ (loss elastic modulus ( G ″) / storage elastic modulus (G ′) ≦ 1} resin is known (Patent Document 1).

JP 2004-63104 A

In the conventional resin for filling an electronic substrate, when the minimum diameter of an opening (through hole, via hole, etc.) provided in the substrate is 0.3 mm or less, an unfilled (cavity due to a dent or void) is generated. There is a problem.
An object of the present invention is to provide a resin for filling an electronic board that is less likely to be unfilled (such as a dent or a void due to a void) even when applied to a small opening (minimum diameter is 0.3 mm or less). is there.

The inventor of the present invention has reached the present invention as a result of intensive studies to solve the above problems. That is, the electronic substrate filling resin of the present invention is characterized in that the non-contact roll (R) and the non-contact roll (R) are in contact with the non-contact roll (R) on the side opposite to the moving direction of the non-contact roll (R) under a pressure of 10 to 10,000 Pa While (R) moving in a straight line at a moving speed (i) (mm / sec) in a direction parallel to the electronic substrate surface and in a direction perpendicular to the rotation axis of (R), (R) ) Is rotated at a peripheral speed (v) (mm / sec) larger than (i) so that the rotation direction of the portion on the electronic substrate side from the rotation axis of () is opposite to the moving direction. An electronic substrate filling resin for the process of filling the opening,
Comprising an inorganic filler (F) and a curable resin (K),
Based on the total weight of the inorganic filler (F) and the curable resin (K), the content of (F) is 55 to 90% by weight, the content of (K) is 10 to 45% by weight,
The inorganic filler (F) comprises a spherical inorganic filler (F1) having a volume average particle diameter of 3 to 8 μm and a non-spherical inorganic filler (F2) having a volume average particle diameter of 0.1 to 3 μm, and the weight of (F) The content of (F1) is 50 to 99% by weight, the content of (F2) is 1 to 50% by weight,
The spherical inorganic filler (F1) is spherical silica and / or spherical metal powder, and the non-spherical inorganic filler (F2) is aluminum oxide surface-treated barium sulfate or aluminum hydroxide surface-treated barium sulfate,
The curable resin (K) comprises bisphenol A type liquid epoxide and / or bisphenol F type liquid epoxide, and a solid curing agent having a volume average particle size of 1 to 8 μm,
All tan δ {loss elastic modulus (G ″) / storage elastic modulus (G ′)} at a frequency of 1 to 10 Hz is 3 to 30, and volatile matter (133 Pa, 80 ° C., 4 hours) is 0.2 weight. The point is below%.

  The resin for filling an electronic substrate of the present invention generates very little unfilling (such as dents or voids due to voids) even when applied to an opening having a minimum diameter of 0.3 mm or less. Therefore, when the resin of the present invention is used, any through hole or via hole can be easily filled.

It is sectional drawing which showed typically the component part of an upper cone type disk and a lower plane disk among the viscoelasticity measuring apparatuses for measuring storage elastic modulus (G ') and loss elastic modulus (G "). It is sectional drawing which showed typically an example of the front-end | tip shape of the front-end | tip of a doctor. It is sectional drawing which showed typically an example of the front-end | tip shape of the front-end | tip of a doctor. It is sectional drawing which showed typically the state at the time of the start of the filling process (Example) of the electronic substrate filling resin of this invention. It is sectional drawing which showed typically the state in the filling process (Example) of the resin for electronic board filling of this invention. It is sectional drawing which showed typically the state at the time of completion | finish of the filling process (Example) of resin for electronic board filling of this invention. It is the perspective view which showed the guard (13) typically. It is a perspective view which shows notionally the positional relationship of a doctor (7), a non-contact roll (8), and a guard (13).

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Upper cone type disk 2 Lower plane disk 3 Vacuum chamber 4 Electronic board fixing stand 5 Release film 6 Electronic board 7 Doctor 8 Non-contact roll (R)
9 Resin for filling electronic substrate 10 Rotating shaft 11 of non-contact roll (R) Via hole 12 Through hole 13 Guard 21 Arrow 22 indicating the direction of sinusoidal vibration 22 Center shaft 26 of the upper cone type disk Arrow 27 indicating the rotating direction of the non-contact roll Arrow indicating the direction of movement of the doctor, non-contact roll and guard

  The tan δ {loss elastic modulus (G ″) / storage elastic modulus (G ′)} of the resin for filling an electronic substrate of the present invention at a frequency of 1 to 10 Hz is preferably 3 to 30, more preferably 5 to 5. 25, particularly preferably 7 to 20, and most preferably 10 to 15. Within this range, generation of unfilled (such as dents and voids due to voids) can be further suppressed.

tan δ {loss elastic modulus (G ″) / storage elastic modulus (G ′)} is “Rheological engineering and its applied technology”, Fuji Techno System Co., Ltd., published on January 12, 2001, first edition, first edition, No. 204 It is the value measured using the viscoelasticity measuring apparatus (For example, HAAKE company make Rheostress RS75) measurable with the stress control system of -206 pages, and is calculated | required as follows.
A measurement sample is sandwiched between measurement jigs {between the upper cone disk 1 and the lower flat disk 2 (see FIG. 1, arrow 21 in FIG. 1 indicates the direction of sinusoidal vibration)}, and the upper surface of the upper cone disk 1 Is generated as a result of applying stress (σ) (unit: Pa) to the measurement sample by sine vibration while changing the frequency (f) (unit: Hz) with the central axis 22 perpendicular to the axis as the axis. Strain (ε) (unit: rad) and phase angle (δ) (unit: rad) are measured. Tan δ is obtained from the phase angle (δ) at a frequency of 1 to 10 Hz.
The loss elastic modulus (G ″) and storage elastic modulus (G ′) are determined in accordance with JIS K7244-1-1998 “Plastics—Test Method for Dynamic Mechanical Properties Part 1: General Rules”. After calculating the complex elastic modulus (G ^* = σ / ε) (unit: Pa) from the ratio (σ / ε) to ε), the real part of the complex elastic modulus (G ^* ) is expressed by the expression {G ′ = G ^The storage elastic modulus (G ′) is calculated from ^* × cos δ}, and the loss elastic modulus (G ″) is calculated from the expression {G ″ = G ^* × sin δ}.

The measurement conditions are shown below.
Measuring device: Dynamic viscoelasticity measuring device (for example, Rheostress RS75 manufactured by HAAKE)
Measuring jig: 20mm diameter aluminum disk (upper cone disk angle 2 degrees)
Sample volume: 0.5mL
Rotational shear stress: 10Pa
Measurement temperature: 23 ° C
Frequency: 1-10Hz

  tan δ is a measure of the ease of deformation of a paste-like object, and the smaller tan δ, the closer it is to a solid, the more difficult it is to deform, and the larger tan δ, the closer to a liquid, the easier it is to deform. When tan δ is less than 3, the paste-like object is more difficult to deform, and voids caught in the paste-like object at the time of filling are further lost. As a result, voids due to residual voids are more likely to occur in the opening after the paste-like object is cured. On the other hand, if tan δ exceeds 30, the paste-like object becomes too deformable, and the paste-like object is more likely to sag before curing. As a result, dents and voids are more likely to occur in the opening.

  The storage elastic modulus (G ′) (unit: Pa) of the resin for filling an electronic substrate of the present invention is preferably 10 to 10,000, more preferably 20 to 1,000, particularly preferably 30 to 500, most preferably at a frequency of 1 Hz. 40-200. Similarly, at a frequency of 5 Hz, 50 to 50000 is preferable, more preferably 100 to 5000, particularly preferably 150 to 2500, and most preferably 200 to 1000. Similarly, at a frequency of 10 Hz, 100 to 100,000 is preferable, more preferably 200 to 10,000, particularly preferably 300 to 5000, and most preferably 400 to 2000. Within these ranges, the occurrence of unfilled (cavities due to dents or voids) can be further suppressed.

  The loss elastic modulus (G ″) (unit: Pa) is preferably 30 to 300,000, more preferably 100 to 25000, particularly preferably 210 to 10,000, and most preferably 400 to 3000 at a frequency of 1 Hz. In particular, at a frequency of 5 Hz, it is preferably from 150 to 1500,000, more preferably from 500 to 125,000, particularly preferably from 1050 to 50000, most preferably from 2000 to 15000. Similarly, at a frequency of 10 Hz, from 300 to 3000000 is preferable, and more preferably. The range is 1000 to 250,000, particularly preferably 2100 to 100000, and most preferably 4000 to 30000. Within this range, generation of unfilled (cavities due to dents or voids) can be further suppressed.

The volatile matter (unit: weight%, 133 Pa, 80 ° C., 4 hours) of the resin for filling an electronic substrate of the present invention is preferably 0.2 or less, more preferably 0.15 or less, particularly preferably 0.1 or less. is there. Within this range, the occurrence of unfilled (cavities due to dents or voids) can be further suppressed.
The volatile matter is measured in accordance with JIS K0067-1992 “Method for testing weight loss and residue of chemical products” 3.1.1 Drying weight loss test method.

  The viscosity of the resin for filling an electronic substrate of the present invention (unit: Pa · s, 23 ° C., JIS Z8803-1991, 8. Viscosity measurement method using a single cylindrical rotational viscometer) is preferably 200 to 2000, more preferably. 300 to 1500, particularly preferably 400 to 1200, and most preferably 450 to 1000. Within this range, the occurrence of unfilled (cavities due to dents or voids) can be further suppressed. In order to prevent void entrainment at the time of filling and curing, it is conceivable that the viscosity is less than the above range to further improve the fluidity and make it easy to escape the void. In this case, the resin for filling the electronic substrate is easily dripped off. As a result, dents and voids are more likely to occur in the opening. On the other hand, in order to prevent dripping of the resin for filling the electronic substrate before curing, it is conceivable to lower the fluidity by setting the viscosity to exceed the above range, but as the viscosity increases, the filling of the resin for filling the electronic substrate is increased. It tends to be difficult.

The resin of the present invention includes an inorganic filler (F) and a curable resin (K), and is not limited as long as tan δ and volatile content are in the above ranges.
As the inorganic filler (F), oxides {silica (silicon oxide), titania (titanium oxide), alumina (aluminum oxide), zirconia (zirconium oxide), barium titanate, etc.}, carbonate {calcium carbonate etc.}, sulfuric acid Examples thereof include salts {barium sulfate and the like}, metals {copper, silver, nickel, tin, tungsten, iron and the like, and composites (including mixed molded products and solid solutions thereof)}. Of these, silica, alumina, copper, silver, barium sulfate and calcium carbonate are preferable, silica, copper and barium sulfate are more preferable, and silica and barium sulfate are particularly preferable.

The inorganic filler (F) may be surface-treated with a coupling agent or an inorganic substance.
Examples of the coupling agent include organic silane coupling agents and organic titanate coupling agents.
As the organic silane coupling agent, compounds described in JP-A No. 2004-277726 can be used. Of these, 3,4-epoxycyclohexylethyltrimethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-gridoxypropylmethyldiethoxysilane and 3-methacryloxypropyltrimethoxysilane are preferable, and 3 is more preferable. -Glycidoxypropyltrimethoxysilane. As the surface treatment method, the method described in JP-A-2003-128938 can be used.

As the titanate coupling agent, compounds described in JP-A No. 2004-238371 can be used. Of these, isopropyl triisostearoyl titanate, isopropyl trioctanoyl titanate, isopropyl dimethacrylisostearoyl titanate and isopropyl isostearoyl diacryl titanate are preferable, and isopropyl triisostearoyl titanate is more preferable.
As a surface treatment method, the method of JP-A-2004-238371 can be applied. When surface-treating with a coupling agent, the amount used (% by weight) is preferably 0.1 to 10, more preferably 0.2 to 5, particularly preferably 0, based on the weight of the inorganic filler before the treatment. .3-2. Within this range, the unfilled opening and the generation of voids are further suppressed.

As the inorganic substance, metal oxides and metal hydroxides described in JP-A-2005-97400 can be used. Of these, aluminum oxide and aluminum hydroxide are preferable, and aluminum oxide is more preferable.
As the surface treatment method, methods described in JP-A-8-217635 and JP-A-10-158015 can be applied.
When surface-treating with an inorganic substance, the amount used (% by weight) is preferably 0.1 to 20, more preferably 0.5 to 10, particularly preferably 1 to 5, based on the weight of the inorganic filler before the treatment. It is. Within this range, the unfilled opening and the generation of voids are further suppressed. In addition, you may surface-treat with a coupling agent after the surface treatment with an inorganic substance.

As the shape of the filler (F), spherical shape, teardrop shape, square shape, dendritic shape, flake shape, granular shape, irregular shape, needle shape and fibrous shape {JIS Z2500: 2000 "Powder and Gold Terms" 4. Terms and definitions, 4) Non-spherical such as powder particle shape}. Of these, spherical, square, granular and irregular shapes are preferred.
The spherical shape includes those having a major axis / minor axis ratio of 1.0 to 1.5, preferably 1.0 to 1.3, and more preferably 1.0 to 1.2. It is.

The volume average particle size (μm) of the filler (F) is preferably 0.1 to 8.0, more preferably 0.2 to 7.5, and particularly preferably 0.3 to 7.0.
Within this range, the unfilled opening and the generation of voids are further suppressed.
In addition, the volume average particle diameter is a laser diffraction particle size distribution measuring apparatus having a measurement principle based on JIS Z8825-1-2001 “Particle Size Analysis—Laser Diffraction Method” (for example, trade name SALD-1100 manufactured by Shimadzu Corporation). Measured in

  Although a filler (F) may be used independently, it is preferable to use combining 2 or more types. When two or more types are used in combination, it is preferable to combine the spherical inorganic filler (F1) and the non-spherical inorganic filler (F2). In this case, the volume average particle size of the spherical inorganic filler (F1) and the non-spherical inorganic filler (F2) is preferably in the following range. That is, the volume average particle diameter (μm) of the spherical inorganic filler (F1) is preferably 3 to 8, more preferably 4 to 7.5, and particularly preferably 5 to 7. Moreover, 0.1-3 are preferable, as for the volume average particle diameter (micrometer) of a non-spherical inorganic filler (F2), More preferably, it is 0.2-2, Most preferably, it is 0.3-1.5. Within this range, the unfilled opening and the generation of voids are further suppressed.

  The spherical inorganic filler (F1) is preferably spherical silica, spherical alumina, spherical copper powder and spherical silver powder, more preferably spherical silica and spherical copper powder, and particularly preferably spherical silica.

  The non-spherical inorganic filler (F2) is preferably crushed silica, granular barium sulfate and granular calcium carbonate, more preferably granular barium sulfate, and particularly preferably granular barium sulfate surface-treated with aluminum oxide or aluminum hydroxide.

The content (% by weight) of the inorganic filler (F) is preferably 55 to 90, more preferably, based on the total weight of the inorganic filler (F) and the curable resin (K) from the viewpoint of the coefficient of thermal expansion. 60 to 85, particularly preferably 65 to 80.
When the spherical inorganic filler (F1) and the non-spherical inorganic filler (F2) are combined, the content (% by weight) of the spherical inorganic filler (F1) is preferably 50 to 99 based on the weight of the inorganic filler (F). More preferably, it is 60-95, Most preferably, it is 70-90. Further, the content (% by weight) of the non-spherical inorganic filler (F2) is preferably 1 to 50, more preferably 5 to 40, and particularly preferably 10 to 30 based on the weight of the inorganic filler (F). . Within this range, the unfilled opening and the generation of voids are further suppressed.

Examples of the curable resin (K) include a thermosetting resin and an active energy ray curable resin.
The thermosetting resin can be used without limitation as long as it is a resin curable by heat, but is preferably a liquid thermosetting resin, more preferably a liquid epoxy resin (consisting of a liquid epoxide and a curing agent).
The liquid epoxide means an epoxide that is liquid at 25 ° C., but also includes an epoxide that is liquid at 25 ° C. together with a liquid epoxide that becomes liquid as a whole. The liquid state means that an object is placed in a vertical test tube (made of flat bottom cylindrical glass having an inner diameter of 30 mm and a height of 120 mm) until the height from the bottom of the test tube becomes 55 mm, and the test tube is placed horizontally. In this case, it means that the time until the tip of the moving surface of the article passes through a portion whose distance from the bottom of the test tube is 85 mm is within 90 seconds. The solid state means a state in which the above time exceeds 90 seconds.

  As the liquid epoxide, liquid epoxides described in Japanese Patent No. 3181424 or Japanese Patent No. 3375835 can be used, and among these, bisphenol F type liquid epoxide, bisphenol A type liquid epoxide, phenol novolac type liquid epoxide, Naphthalene type liquid epoxide and glycidylamine type liquid epoxide are preferable, and bisphenol F type liquid epoxide and bisphenol A type liquid epoxide are more preferable.

  Examples of the solid epoxide include bisphenol A type epoxide (epoxy equivalent 300 to 5000), bisphenol F type epoxide (epoxy equivalent 500 to 10,000), cresol novolac epoxide (epoxy equivalent 195 to 240), biphenyl type epoxide (epoxy equivalent). 158 to 198), trishydroxyphenylmethane type epoxide (epoxy equivalents 162 to 176), dicyclopentagen phenol type epoxide (epoxy equivalents 250 to 300), and the like can be used.

  As the curing agent, any curing agent can be used as long as it reacts with the epoxide to give a cured product, but a solid curing agent (phenol compound, dicyandiamide, imidazole compound, organic acid hydrazide compound, amine adduct compound, etc.) is preferable, More preferred are dicyandiamide, imidazole compounds and amine adduct compounds, and particularly preferred are imidazole compounds. These curing agents may be used alone or in combination of two or more.

Examples of the phenol compound include cresol novolak resin (weight average molecular weight 320 to 32,000), phenol novolak resin (weight average molecular weight 360 to 36,000), naphthylcresol, tris (hydroxyphenyl) methane, dinaphthyltriol, tetrakis ( 4-hydroxyphenyl) ethane and 4,4-oxybis (1,4-phenylethyl) tetracresol.
The weight average molecular weight is measured by gel permeation chromatography using polystyrene having a known molecular weight as a standard substance.

  Examples of imidazole compounds include 2-undecylimidazole, 2-heptadecylimidazole, 2-phenylimidazole, 1-benzyl-2-methylimidazole, 1-cyanoethyl-2-methylimidazole, 1-cyanoethyl-2-undecylimidazole. 2-phenyl-4,5-dihydroxymethylimidazole, 2-phenyl-4-methyl-5-hydroxymethylimidazole, 1-cyanoethyl-2-phenyl-4,5-di (cyanoethoxymethyl) imidazole, 1-cyanoethyl 2-undecylimidazolium trimellitate, 1-cyanoethyl-2-phenylimidazolium trimellitate, 2-methylimidazolium isocyanurate, 2-phenylimidazolium isocyanurate, 1-dodecyl-2-meth Til-3-benzylimidazolium chloride, 1,3-dibenzyl-2-methylimidazolium chloride, 2,4-diamino-6- [2-methylimidazolyl- (1H)]-ethyl-S-triazine, 2 , 4-Diamino-6- [2-ethyl-4-methylimidazolyl- (1H)]-ethyl-S-triazine and 2,4-diamino-6- [2-undecylimidazolyl- (1H)]-ethyl- S-triazine etc. are mentioned.

  Examples of the organic acid hydrazide compound include phenylaminopropionic hydrazide, p-oxybenzoic acid hydrazide, salicylic acid hydrazide, succinic acid dihydrazide, adipic acid dihydrazide, and isophthalic acid dihydrazide.

As an amine adduct compound, there is no limitation as long as it does not dissolve in epoxide at 0 to 40 ° C. (it hardly acts as a curing agent), but dissolves (acts as a curing agent) by heating to 80 to 150 ° C. A reaction product of amine and epoxy resin (amine-epoxy adduct), a reaction product of amine and isocyanate or urea (urea type adduct), and the like (Japanese Patent No. 3391704) can be used. In addition to this, a product obtained by treating the surface of these reaction products with an isocyanate or an acidic compound (Japanese Patent No. 3391704) can be used.
Amine adduct compounds can be easily obtained from the market, and trade names include Amicure PN-23J, Amicure PN-31, Amicure PN-31J, Amicure PN-40, Amicure PN-40J, Amicure PN-D, Amicure MY-H. , Amicure MY-HK and Amicure MY-D (both manufactured by Ajinomoto Fine Techno Co., Ltd.).

  1-8 are preferable, as for the volume average particle diameter (micrometer) of a solid hardening | curing agent, More preferably, it is 2-7, Most preferably, it is 3-6. Within this range, the occurrence of unfilled (cavities due to dents or voids) can be further suppressed.

  As for content (weight%) of a solid hardening | curing agent, 3-15 are preferable based on the weight of curable resin (K), More preferably, it is 5-12, Most preferably, it is 6-10. Within this range, the occurrence of unfilled (cavities due to dents or voids) can be further suppressed.

The active energy ray-curable resin can be used without limitation as long as it is a resin that is cured by active energy rays (preferably ultraviolet rays and electron beams, more preferably ultraviolet rays), but liquid compounds having a polymerizable double bond and photoradicals. A composition comprising a generator is preferred.
As the compound having a polymerizable double bond, a liquid compound having a polymerizable double bond described in Japanese Patent Laid-Open No. 2001-330951 can be used.
Among these, polyhydric alcohol or polyhydric alcohol alkylene oxide adduct and (meth) acrylic acid ester {dipentaerystol hexa (meth) acrylate, ethoxylated trimethylolpropane tri (meth) acrylate, etc.}, urethane (Meth) acrylate {isocyanatoethyl (meth) acrylate, reaction product of polyisocyanate and (meth) acrylate having active hydrogen-containing groups (hydroxy group, carboxy group, amino group, etc.) (hexamethylene diisocyanate and hydroxyethyl acrylate) Etc.) and epoxy (meth) acrylate {reaction product of polyfunctional epoxide and (meth) acrylic acid: bisphenol A diglycidyl ether di (meth) acrylate and phenol novolac (meth) acrylate Etc.} is preferably an ester of more preferably a polyhydric alcohol or an alkylene oxide adduct of polyhydric alcohol and (meth) acrylic acid.
These compounds having a polymerizable double bond may be used alone or in combination of two or more.
In the present invention, “... (Meth) acryl ...” means “... acrylic ...”, “... metacri ...”.

As the photoradical generator, compounds described in JP 2001-330951 A can be used.
Of these, diphenyl- (2,4,6-triethylbenzoyl) phosphine oxide, 2,2-dimethoxy-2-phenylacetophenone, dimethylhydroxyacetophenone, 1-hydroxy-cyclohexyl-phenyl-ketone, 2-benzyl-2 -Dimethylamino-1- (4-morpholinophenyl) -butanone and 2-methyl-1 [4- (methylthio) phenyl] -2-morpholinopropan-1-one are preferred. These photo radical generators may be used alone or in combination of two or more.

  The curable resin (K) may be used alone or in combination with a thermosetting resin and an active energy ray curable resin. When the thermosetting resin and the active energy ray curable resin are used in combination, the content (% by weight) of the active energy ray curable resin is 5 based on the total weight of the thermosetting resin and the active energy ray curable resin. -70 are preferable, More preferably, it is 10-60, Most preferably, it is 15-50. Within this range, the occurrence of unfilled (cavities due to dents and voids) can be further suppressed.

  The content (% by weight) of the curable resin (K) is preferably 10 to 45, more preferably 15 to 40, particularly preferably based on the total weight of the inorganic filler (F) and the curable resin (K). 20-35. Within this range, the occurrence of unfilled (cavities due to dents or voids) can be further suppressed.

The resin for filling an electronic substrate of the present invention may contain a commonly used additive {antifoaming agent, dispersant, organic / inorganic colorant, flame retardant and / or thixotropic agent}.
As the antifoaming agent, "the latest technology of coating additives", CMC Co., Ltd., February 27, 2001, first printing issued, Nos. 73-82, pages 252-256, etc. are used. A silicone antifoaming agent is preferred.
Examples of the dispersant include those described in Japanese Patent No. 2603553, and examples thereof include phosphate ester compounds, propylene oxide addition ester compounds, and higher fatty acids.
Examples of the organic / inorganic colorant include titanium oxide, carbon black, and phthalocyanine blue.
As the flame retardant, flame retardants described in “Latest Technology of Coating Additives”, CMC Co., Ltd., February 27, 2001, First Printing, pages 191 to 199, pages 275 can be used. Aluminum hydroxide and a triazine compound are preferable, and a silicone compound and a triazine compound are more preferable.
As the thixotropic agent, “the latest technology of coating additives”, CMC Co., Ltd., published on February 27, 2001, the first printing, pages 59-71, pages 249-251, etc. are used. Organic polyamide wax and hydrogenated castor oil wax are preferable, and organic polyamide wax is more preferable.

  When an antifoaming agent is added, the content (% by weight) is preferably 0.01 to 5, more preferably 0.05 to 4, particularly preferably 0, based on the weight of the curable resin (K). .1-3. When the dispersant is added, the content (% by weight) is preferably 0.01 to 5, more preferably 0.05 to 4, particularly preferably 0.1 based on the weight of the curable resin (K). ~ 3. When an organic / inorganic colorant is added, the content (% by weight) is preferably 0.01 to 5, more preferably 0.05 to 4, particularly preferably based on the weight of the curable resin (K). 0.1-3. When the flame retardant is added, the content (% by weight) is preferably 0.5 to 10, more preferably 0.8 to 8, particularly preferably 1 to 1, based on the weight of the curable resin (K). 5. When a thixotropic agent is added, the content (% by weight) is preferably 0.01 to 5, more preferably 0.05 to 4, particularly preferably 0. 0 based on the weight of the curable resin (K). 1-3.

Tan δ of the resin for filling an electronic substrate of the present invention is an inorganic filler (F) {content, volume average particle diameter and / or shape, etc.}, curable resin (K) and / or additive (particularly thixotropic agent; type And content).
That is, the factor that affects tan δ is mainly the interaction between particles such as fillers. When the interaction between particles is small, tan δ tends to increase, and when the interaction between particles is large, tan δ tends to decrease. Yes {"Rheological engineering and its applied technology", Fuji Techno System Co., Ltd., January 12, 2001, first edition, first edition, pp. 170-198}.
When no filler or thixotropic agent is contained, tan δ is a value of 10,000 or more, and when a large amount of filler or thixotropic agent is contained, tan δ can be lowered to a value close to zero.

In the case of control using a filler, even if the content is the same, the influence on tan δ varies depending on the particle size, shape, and surface state of the filler. As the particle size of the filler increases, tan δ tends to increase. In addition, tan δ does not easily decrease even when the content of the spherical filler is increased, but tan δ tends to decrease with a small amount of non-spherical filler (particularly a dendritic filler).
In the case of control using a curable resin and / or an additive, the more functional groups and bonds that easily interact with the filler (hydroxyl group, amino group, carbonyl group, ether bond, ester bond, amide bond, etc.), the smaller the tan δ. Prone.
Of the additives, the thixotropic agent has a small tan δ due to chemical action such as hydrogen bonding or adsorption, but when used in combination with a filler, the tan δ can be reduced with a small amount of addition. Conversely, tan δ is likely to change greatly due to slight fluctuations in the content of the thixotropic agent. On the other hand, additives other than thixotropic agents have a small effect on tan δ, and since this addition amount is not large, it is difficult to control tan δ with additives other than thixotropic agents.
Therefore, tan δ is preferably controlled by the inorganic filler (F) (particle size, shape, content, etc.) and the curable resin (K), and more preferably by the non-spherical inorganic filler (F2) and the thermosetting resin. Control, particularly preferably using a non-spherical inorganic filler composed of granular barium sulfate surface-treated with aluminum oxide or granular barium sulfate surface-treated with aluminum hydroxide, and a liquid epoxy resin (liquid epoxide and curing agent) Most preferably, the granular barium sulfate surface-treated with aluminum oxide or the granular barium sulfate surface-treated with aluminum hydroxide, and the bisphenol A type liquid epoxide and / or bisphenol F type liquid epoxide, and the volume average particle diameter is 1 to 8 μm. It is to control with a solid curing agent.

  The resin for filling an electronic substrate of the present invention is obtained by uniformly stirring and mixing the inorganic filler (F), the curable resin (K) and, if necessary, the additive. The mixer is not particularly limited as long as it can be uniformly stirred and mixed. For example, a planetary mixer, a three-roll mill, a two-roll mill, a kneader, an extruder, and a high-speed disperser can be used.

The stirring / mixing temperature (° C.) is preferably 5 to 40, more preferably 10 to 35, and particularly preferably 20 to 30 from the viewpoint of preventing abnormal curing or gelation of the curable resin (K). .
The mixing time can be appropriately determined depending on the type and size of the mixer and is not limited as long as uniform mixing is possible, but is preferably 30 to 200 minutes, more preferably 45 to 120 minutes, and particularly preferably 60 to 90 minutes. . In addition, you may mix, reducing pressure in the case of mixing.

Next, a method for applying the electronic substrate filling resin of the present invention will be described.
The electronic substrate filling resin of the present invention is used to fill openings (through holes, via holes, etc.) and the like, and is particularly suitable for filling openings present in an electronic substrate.
As applicable electronic boards, copper-clad laminates for printed wiring boards defined by JIS C 6480-1994 “General Rules for Copper-clad Laminates for Printed Wiring Boards” (glass cloth base epoxy resin, glass cloth base polyimide resin, glass Fabric base bismaleimide / triazine / epoxy resin, etc.). In addition, the present invention can also be applied to an electronic substrate mixed with a thermoplastic resin (polyphenylene ether or the like) and an inorganic filler (silica or the like), a silicon wafer, or the like. Further, the present invention can also be applied to a printed wiring board core substrate in which a circuit is formed or an insulating layer is formed using a copper-clad laminate, a substrate in which a part of the substrate is scraped and a concave portion is formed for component mounting.

  An opening existing in an electronic board is a through hole or bottomed hole formed in the electronic board using a drill or a carbon dioxide laser or the like, and a through hole or bottomed hole in which a conductor is formed by plating in the through hole is plated. It means a via hole formed with a conductor.

The method for filling the opening of the electronic substrate using the resin for filling an electronic substrate of the present invention is not particularly limited, and a screen printing method, a roll coater printing method, and the like can be applied. Is preferred. That is, a non-contact roll (R) under a pressure of 10 to 10000 Pa and a doctor arranged in contact with or in close proximity to the non-contact roll (R) on the side opposite to the moving direction of the non-contact roll (R) While rotating linearly at a moving speed (i) (mm / second) in the direction perpendicular to the rotation axis of (R) with respect to the substrate surface, the rotation of the portion on the electronic substrate side from the rotation axis of (R) A method in which an opening provided in an electronic substrate is filled with an electronic substrate filling resin by rotating at a peripheral speed (v) (mm / second) larger than (i) so that the direction is opposite to the moving direction. It is. When the resin for filling an electronic substrate of the present invention is used in the process comprising such a filling method, the occurrence of unfilled (cavity due to dents or voids) can be further suppressed.
Here, the linear movement of the non-contact roll (R) may be performed by relatively linearly moving the non-contact roll (R) and the substrate. Accordingly, the non-contact roll (R) may move with respect to the stopped substrate, or the substrate moves with respect to the non-contact roll (R) that is stopped (rotating). Good.

  The non-contact roll (R) has no limitation on the speed as long as it can move linearly while keeping the rotation axis horizontal to the surface of the electronic substrate, but the linear movement speed (i) (mm / second) of the non-contact roll (R). ) Is preferably 5 to 100, more preferably 10 to 70, and particularly preferably 20 to 50. Within this range, the occurrence of unfilled (cavities due to dents or voids) can be further suppressed.

The movement direction of the non-contact roll (R) is perpendicular to the rotation axis of (R), but the angle between the movement direction and the rotation axis is not limited to 90 ° but includes 60 to 120 °. It is a waste.
The rotation direction of the non-contact roll (R) is the direction in which the rotation direction of the portion closer to the electronic substrate than the rotation axis is opposite to the movement direction, that is, the direction of rotation so that the non-contact roll (R) rolls in the linear movement direction. It is. This opposite direction (the direction in which the rotation direction of the part closer to the electronic substrate than the rotation axis is the same as the movement direction, that is, the non-contact roll (R) rolls in the direction opposite to the linear movement direction. ), The generation of unfilled (cavity due to dents or voids) cannot be effectively suppressed.

The peripheral speed (v) (mm / second) of the non-contact roll (R) is represented by {Roll angular velocity (ω)} × {Roll radius (r)}, and the moving speed (i) and the peripheral speed (v ) Preferably satisfies (v)> (i), more preferably satisfies the formula (1), and particularly preferably satisfies the formula (2). When this relationship is satisfied, generation of unfilled (cavity due to dents or voids) can be further suppressed.
That is, as the filling volume increases, a larger amount of resin needs to be supplied to the opening. Therefore, it is preferable to increase the peripheral speed (v) to increase the filling force. On the other hand, if the peripheral speed (v) is increased too much, it is likely to cause unfilling (cavity due to dents or voids). Therefore, the peripheral speed (v) preferably satisfies Expression (1), more preferably Expression (2). ).
(Formula (1))
(I) × 20 ≧ (v) ≧ (i) × (1 + t × d) (1)
(Formula (2))
(I) × 10 ≧ (v) ≧ (i) × (1.5 + t × d) (2)
Note that t represents the depth (mm) of the opening, and d represents the diameter of the opening. When there are openings having different depths and diameters in the same substrate, the maximum value of t × d is applied.

  The depth (t) (mm) of the opening is the substrate thickness when the opening is a through hole (through hole), and is usually about 0.4 to 1.6, but in some cases less than 0.4 The present invention can also be applied to a thin plate substrate (0.1 or less), a thick plate substrate exceeding 1.6 (3.0 or more), and the like. On the other hand, when the opening is a via hole (bottomed hole), the depth (t) (mm) of the opening is often 0.1 or less. The depth (t) of the opening is measured in accordance with JIS C5012-1993 “Printed Wiring Board Test Method”.

  The diameter (d) (mm) of the opening represents the opening diameter of a through hole (through hole) or a via hole (bottomed hole), and is usually about 0.1 to 0.5, but in some cases 0.1 The present invention can also be applied to a small-diameter substrate of less than (0.05 or less) and a large-diameter substrate of more than 0.5 (1.0 or more). The diameter (d) of the opening is measured according to JIS C5012-1993 “Printed Wiring Board Test Method”.

The non-contact roll (R) is preferably provided with a doctor {squeegee for scraping off the resin for filling the electronic substrate}. The doctor is arranged so as to be in contact with or close to the non-contact roll (R) on the side opposite to the moving direction of the non-contact roll (R), and moves linearly with the non-contact roll (R). Further, it is preferable that the distal end portion of the doctor on the moving direction side has a plane having an angle of 5 to 45 ° with respect to the electronic substrate, and this angle is more preferably about 15 ° (FIGS. 2 and 3). reference).
The presence of the doctor further reduces unfilled openings (cavities due to dents and voids). That is, the doctor has a function of moving the electronic substrate filling resin collected by the rotation of the non-contact roll (R) in the moving direction together with (R) {not leaving an excessive filling resin on the substrate surface}. Further, the electronic substrate filling resin scraped between the doctor, the non-contact roll (R), and the electronic substrate has a function of maintaining a pressurized state {pressed by the rotation of the non-contact roll (R). This pressurized state generates an action of pushing the filling resin into the opening}.
When arranging a doctor, guards (dam plates) are provided at both ends of the "doctor, non-contact roll (R) and substrate" so that a sealed space is formed between the doctor, non-contact roll (R) and the substrate. ) (For example, FIGS. 7 and 8). This guard moves linearly together with the non-contact roll (R) and the doctor.

  The shortest distance (mm) between the surface of the electronic substrate and the surface of the non-contact rotating roll (R) is preferably 0.1 to 5, more preferably 0.3 to 3, particularly preferably from the viewpoint of filling properties. 0.5 to 1.5. Within this range, the occurrence of unfilled (cavities due to dents or voids) is further suppressed.

  The atmospheric pressure (Pa) in the filling step is preferably 10 to 10,000, more preferably 50 to 5000, and particularly preferably 100 to 1000 from the viewpoint of filling properties. Within this range, the occurrence of unfilled (cavities due to dents or voids) is further suppressed.

When the electronic substrate filling resin filled in the filling process is returned to atmospheric pressure, a dent may be generated due to volume reduction. In order to fill the dent, the resin is filled under atmospheric pressure after the filling process. It is preferable to provide a step {atmospheric pressure replenishment step}.
The filling step may be performed a plurality of times on the same electronic substrate surface. By performing the atmospheric pressure replenishment step after performing the filling step a plurality of times, the occurrence of unfilling (cavities due to dents and voids) is further suppressed.

Filling step {Including an atmospheric pressure replenishment step if necessary. The same applies hereinafter. }, It is preferable to carry out a temporary curing step. In the temporary curing step, heat treatment is performed when the resin for filling the electronic substrate is a thermosetting resin, and irradiation treatment of active energy rays such as ultraviolet rays is performed when the resin is an active energy ray curable resin. When the pre-curing step is followed by polishing in the flattening step, it is preferable that the resin for filling the electronic substrate is in a semi-cured state in order to reduce the polishing load. In this case, heating is performed at 100 to 140 ° C. for about 10 to 50 minutes. When the electronic substrate filling resin is an active energy ray curable resin, UV irradiation of 0.1 to 1 J / cm ² is preferable.

After the filling step, a flattening step of polishing and removing the thin film-like residue of the cured resin remaining on the substrate surface may be provided. The flattening step is performed using a non-woven cloth roll buff, a ceramic roll buff, a belt sander or the like.
A post-curing step may be provided after the planarization step. The post-curing process is performed in order to completely cure, for example, when the semi-cured state is set in order to reduce the polishing load in the planarization process. When the electronic substrate filling resin is a thermosetting resin, it is heated at 150 to 180 ° C. for about 10 to 120 minutes. When the resin for filling an electronic substrate is an active energy ray curable resin, ultraviolet irradiation of about 1 to 5 J / cm ² is preferable.
The curing shrinkage (volume%) of the resin for filling an electronic substrate of the present invention is preferably 2.0 or less, more preferably 1.5 or less, particularly preferably 1.0 or less, from the viewpoint of the dent of the opening. is there. The cure shrinkage (volume%) is determined according to JIS K6901-1999 “Method for Testing Liquid Unsaturated Polyester Resin”, Annex 3 Volume Shrinkage {Heat-curing (150 ° C. × 1 hour) or UV-curing (1 J / cm ² )}.

  The filling step may include a step of simultaneously filling openings having different diameters and / or depths of the openings. The process of simultaneously filling openings having different diameters and / or depths is a process of simultaneously filling through holes (through holes) having different diameters, and simultaneously filling via holes (bottomed holes) having different diameters. A step of simultaneously filling a through hole (through hole) and a via hole (bottomed hole) having the same opening diameter, a step of simultaneously filling a through hole (through hole) and a via hole (bottomed hole) having different opening diameters Etc. The case where the opening diameters are different includes, for example, at least two combinations selected from the group consisting of an opening diameter of 50 μm, an opening diameter of 500 μm, and an opening diameter of 2000 μm. Examples of the case where the depths are different include a combination of a via hole having a depth of 30 μm and a through hole having a depth of 3.2 mm.

  In the filling step, the recesses between the circuits formed on the surface of the electronic substrate can be filled simultaneously with the filling of the openings. A recess between circuits means an inter-circuit portion of a circuit pattern formed by etching a copper foil of a copper-clad laminate or an inter-circuit portion of a circuit pattern formed by copper plating on an insulating substrate.

  When the electronic substrate filling resin of the present invention is applied to the above filling process, it can be filled without using a printing mask, but if there are openings or the like that do not want to be filled, or electrode bumps on the electronic substrate If it is desired to create a discharge section such as a printing mask, a printing mask may be used during filling. A printing mask is placed on an electronic board, and has a through hole at a position corresponding to the opening that needs to be filled, and a stainless steel metal mask plate, polyester resin film, and screen mesh plate covering the portions that do not need filling. A photosensitive film can be used.

When there are via holes (bottomed holes) on both sides of the electronic substrate, the electronic substrate surface opposite to the filled electronic substrate surface is filled in the same manner.
A so-called build-up multilayer printed wiring is obtained by laminating insulating layers and / or wiring layers (alternately) on the resin-filled substrate thus obtained (if necessary, the above filling step may be further provided). A board can be obtained {"Printo Banjuku build-up wiring board introduction for new employees", published by Japan Electronic Circuits Association (2001)}.
For example, the wiring layer is filled with resin in the opening and cured (including the case where the resin layer is formed on the substrate surface), then roughened by desmear treatment, etc., electroless plating (copper, etc.) and electrolysis The conductive layer is formed by plating (copper or the like) and unnecessary portions are removed by etching or the like.
In the electronic substrate filling resin of the present invention, since the opening after filling is excellent in flatness (since no dent is generated), a wiring layer having a uniform conductor thickness and width can be easily formed.

EXAMPLES The present invention will be described below with reference to examples, but the present invention is not limited to the following examples. Unless otherwise specified, parts mean parts by weight and% means% by weight.
<Example 1>
Spherical inorganic filler {(F11); Tatsumori Co., Ltd. TSS8 (spherical silica having a volume average particle size of 7.5 μm} 47 parts, non-spherical inorganic filler {(F21); B-34 (manufactured by Sakai Chemical Industry Co., Ltd.) 15 parts of aluminum oxide surface-treated barium sulfate powder having a volume average particle size of 0.3 μm)}, curable resin {(K1); liquid epoxide A (Epicoat 807 (bisphenol F type liquid epoxide) manufactured by Japan Epoxy Resin Co., Ltd.) .5 parts and a curing agent A (imidazole 2MZA-PW (2,4-diamino-6- [2'-methylimidazolyl- (1 ')]-ethyl-s-triazine, manufactured by Shikoku Kasei Co., Ltd.), volume average particle (Mixture with 2.5 parts in diameter) 2.5 parts} and additive {antifoaming agent A; KF6002 (carbinol-modified silicone) manufactured by Shin-Etsu Chemical Co., Ltd.} Was put on Seisakusho PLM-50), revolution speed: 20 rpm and the temperature at 22 ° C., and premixed for 30 minutes to obtain a premix body.
Subsequently, this premixed body is kneaded with three rolls (HHC-178X356 manufactured by Inoue Seisakusho Co., Ltd., pressure between rolls: 3 MPa, temperature: 22 ° C., number of passes: 2 times), and for filling the electronic substrate of the present invention. Resin 1 was obtained.
The storage elastic modulus (G ′) and loss elastic modulus (G ″) of the resin 1 for filling an electronic substrate were measured at 23 ° C. and a stress of 10 Pa using a viscoelasticity measuring device (HAAKE Corp. Rheo Stress RS75). Table 1a shows the storage elastic modulus (G ′), loss elastic modulus (G ″) and tan δ calculated from these at 5 and 10 Hz.
Moreover, the volatile matter of the resin 1 for electronic board filling was measured using the reduced pressure drying apparatus (LHV110 by Tabai, sample amount 5g, 133Pa, 80 degreeC, 4 hours), and it was shown in Table 1a.
Moreover, the viscosity of the resin 1 for electronic board | substrate filling was measured using BH type viscosity measuring apparatus (Toki Sangyo Co., Ltd. TV-20, A7 rotor, 23 degreeC, 2 rpm), and it showed to Table 1a.
Further, the cure shrinkage was measured and shown in Table 1a.

<Examples 2 to 14>
47 parts of spherical inorganic filler (F11), 15 parts of non-spherical inorganic filler (F21), curable resin (K1) {mixture of liquid epoxide A34.5 parts and curing agent A2.5 parts} and additive {antifoaming agent A1 part} is changed to the composition {spherical inorganic filler, non-spherical inorganic filler, curable resin and additive} and the amount used shown in Table 1, and the resin for filling an electronic substrate of the present invention is the same as in Example 1. 2-14 were obtained.
For the electronic substrate filling resins 2 to 14, the storage elastic modulus (G ′), the loss elastic modulus (G ″), tan δ calculated from these, the volatile content, the viscosity, and the curing shrinkage rate are the same as in Example 1. Measured and shown in Table 1a or Table 1b, except that the resin for filling an electronic substrate of Examples 11 and 12 was not heat-treated (130 ° C., 30 minutes), but 1 J / cm ² (integrated light amount of wavelength 365 nm). UV cured.

<Comparative Examples 1-6>
47 parts of spherical inorganic filler (F11), 15 parts of non-spherical inorganic filler (F21), curable resin (K1) {mixture of liquid epoxide A34.5 parts and curing agent A2.5 parts} and additive {antifoaming agent Resin for filling a comparative electronic substrate in the same manner as in Example 1 except that A1 part} is changed to the comparative composition {spherical inorganic filler, non-spherical inorganic filler, curable resin and additive} and the amount used shown in Table 2 1-6 were obtained.
For the comparative electronic substrate filling resins 1 to 6, the storage elastic modulus (G ′), the loss elastic modulus (G ″), tan δ calculated from these, the volatile content, the viscosity, and the volume shrinkage are the same as in Example 1. The resin for filling a comparative electronic substrate of Comparative Example 6 is not a heat treatment (130 ° C., 30 minutes), but an ultraviolet ray of 1 J / cm ² (integrated light amount of wavelength 365 nm). Cured.

・球状無機フィラー
（Ｆ１１）：（株）龍森製 ＴＳＳ８（体積平均粒径７．５μｍの球状シリカ）
（Ｆ１２）：（株）龍森製 ＭＳＳ４（体積平均粒径３．５μｍの球状シリカ）
（Ｆ１３）：福田金属箔粉（株）製 ＳＲＣ−Ｃｕ−１５（体積平均粒径１２μｍの球状銅粉）
（Ｆ１４）：アドマテックス（株）製 ＳＯ−Ｃ５（体積平均粒径１．５μｍの球状シリカ）
（Ｆ１５）：日本アトマイズ加工（株）製 ＨＸＲ−Ｃｕ（体積平均粒径５．０μｍの球状銅粉）
（Ｆ１６）：（株）龍森製 ＣＲＳ１１０１ＣＥ（体積平均粒径１．５μｍのグリシドキシプロピルトリメトキシシラン表面処理球状シリカ）

・非球状無機フィラー
（Ｆ２１）：堺化学工業（株）製 Ｂ−３４（体積平均粒径０．３μｍの酸化アルミニウム表面処理硫酸バリウム粉）
（Ｆ２２）：日東粉化工業（株）製 ＴＳＳ＃１０００（体積平均粒径１．２μｍの重質炭酸カルシウム）
（Ｆ２３）：（株）龍森製 ＲＤ−８（体積平均粒径１５μｍの不定形破砕シリカ）
（Ｆ２４）：日本アエロジル（株）製Ｒ２０２（体積平均粒径１４ｎｍの疎水性不定形シリカ）

・硬化性樹脂（Ｋ１）〜（Ｋ８）：液状エポキシドと硬化剤との混合物
（Ｋ９）：液状エポキシド、硬化剤、重合性二重結合を有する化合物及び光ラジカル発生剤の混合物
液状エポキシド
（Ａ）：ジャパンエポキシレジン（株）製 エピコート８０７（ビスフェノールＦ型液状エポキシド）
（Ｂ）：大日本インキ工業（株）製 エピクロン８４０Ｓ（ビスフェノールＡ型液状エポキシド）
硬化剤
（Ａ）：四国化成（株）製イミダゾール ２ＭＺＡ−ＰＷ（２，４−ジアミノ−６−〔２’−メチルイミダゾリル−（１’）〕−エチル−ｓ−トリアジン、体積平均粒径４μｍ）
（Ｂ）：四国化成（株）製イミダゾール ２Ｅ４ＭＺ−ＣＮ（１−シアノエチル−２−エチル−４−メチルイミダゾール、液状）
重合性二重結合を有する化合物
（ＤＰＰＡ）：サンノプコ（株）製ノプコマー４５１０（ジペンタエリストールペンタアクリレート）
光ラジカル発生剤：チバスペシャリティーケミカルス（株）製 イルガキュア１８４

・非硬化性樹脂
熱可塑性樹脂：日新化学（株）製エトセル（ヒドロキシエチルセルロース）

・添加剤
消泡剤Ａ：信越化学（株）製ＫＦ６００２（カルビノール変性シリコーン）
消泡剤Ｂ：共栄社（株）性ＡＣ３２６Ｆ（アクリルコポリマー）
揺変剤Ａ：楠本化成（株）製ディスパロン３９００（ポリアマイド、溶剤３０％含有）
溶剤Ａ：キシレン
溶剤Ｂ：ブチルカルビトール

-Spherical inorganic filler (F11): Tatsumori Co., Ltd. TSS8 (spherical silica having a volume average particle size of 7.5 μm)
(F12): Tatsumori Co., Ltd. MSS4 (spherical silica having a volume average particle size of 3.5 μm)
(F13): SRC-Cu-15 (spherical copper powder having a volume average particle diameter of 12 μm) manufactured by Fukuda Metal Foil Powder Co., Ltd.
(F14): Admatechs Co., Ltd. SO-C5 (spherical silica having a volume average particle size of 1.5 μm)
(F15): HXR-Cu (spherical copper powder having a volume average particle size of 5.0 μm) manufactured by Nippon Atomizing Co., Ltd.
(F16): Tatsumori Co., Ltd. CRS1101CE (Glycidoxypropyltrimethoxysilane surface-treated spherical silica having a volume average particle size of 1.5 μm)

Non-spherical inorganic filler (F21): B-34 manufactured by Sakai Chemical Industry Co., Ltd. (aluminum oxide surface-treated barium sulfate powder having a volume average particle size of 0.3 μm)
(F22): TSS # 1000 (heavy calcium carbonate having a volume average particle size of 1.2 μm) manufactured by Nitto Flour Chemical Co., Ltd.
(F23): RD-8 manufactured by Tatsumori Co., Ltd. (amorphous crushed silica having a volume average particle size of 15 μm)
(F24): Nippon Aerosil Co., Ltd. R202 (hydrophobic amorphous silica having a volume average particle size of 14 nm)

Curing resins (K1) to (K8): A mixture of liquid epoxide and curing agent
(K9): Liquid epoxide, curing agent, mixture of polymerizable double bond and photo radical generator Liquid epoxide (A): Japan Epoxy Resin Co., Ltd. Epicoat 807 (bisphenol F type liquid epoxide)
(B): Daikoku Ink Industries, Ltd. Epicron 840S (bisphenol A liquid epoxide)
Curing agent (A): Shikoku Kasei Co., Ltd. imidazole 2MZA-PW (2,4-diamino-6- [2′-methylimidazolyl- (1 ′)]-ethyl-s-triazine, volume average particle size 4 μm)
(B): Shikoku Kasei Co., Ltd. imidazole 2E4MZ-CN (1-cyanoethyl-2-ethyl-4-methylimidazole, liquid)
Compound having a polymerizable double bond (DPPA): Nopcomer 4510 (dipentaerystol pentaacrylate) manufactured by San Nopco Co., Ltd.
Photoradical generator: Irgacure 184, manufactured by Ciba Specialty Chemicals

・ Non-curable resin Thermoplastic resin: Nisshin Chemical Co., Ltd. etosel (hydroxyethylcellulose)

Additives Antifoam A: Shin-Etsu Chemical Co., Ltd. KF6002 (carbinol-modified silicone)
Antifoam B: Kyoeisha Co., Ltd. AC326F (acrylic copolymer)
Thixotropic agent A: Dispalon 3900 (Polyamide, containing 30% solvent) manufactured by Enomoto Kasei Co., Ltd.
Solvent A: Xylene Solvent B: Butyl carbitol

<Evaluation>
(1) Filling device (see FIGS. 2 to 8)
The filling device is one in which an electronic substrate fixing base (4), a doctor (7), a non-contact roll (8) and a guard (13) are arranged in a vacuum chamber (3) {manufactured by Tokai Shoji Co., Ltd., A vacuum coater SVM} was used.
The doctor (7), the non-contact roll (8) and the guard (13) are integrally moved horizontally with respect to the surface of the electronic substrate and perpendicular to the rotation axis of the non-contact roll (8). A linear movement can be performed at a speed (i) (mm / sec). The moving directions of the doctor (7), the non-contact roll (8) and the guard (13) are shown by arrows 27 in FIGS.
Further, the doctor (7) can scrape off excess electronic substrate filling resin remaining on the substrate after the electronic substrate filling resin (9) is filled in the opening of the electronic substrate.
The inside of the vacuum chamber (3) can be depressurized.
Further, the non-contact roll (8) is configured such that the rotation direction of the portion on the electronic substrate side with respect to the rotation axis of the non-contact roll (8) is opposite to the moving direction of the doctor (7) and the non-contact roll (8). Thus, it can be rotated at a peripheral speed (v) (mm / sec). In FIG. 5, the direction of rotation of the non-contact roll (8) is indicated by an arrow 26.
The surface material of the non-contact roll (8) is made of stainless steel, and its size is 50 mm in diameter and 550 mm in length. The doctor (7) is made of urethane resin having a hardness of 80 degrees, and has a width of 70 mm, a thickness of 20 mm, and a length of 550 mm, and the tip has the shape shown in FIG.
The guard (13) can prevent the resin paste (J) from protruding from both end portions of the doctor (7) and the non-contact roll (8). The guard (13) is a polyacetal plate (height 80 mm, width 100 mm, thickness 20 mm) provided with a through hole with a diameter of 51 mm at the center (the through hole is a non-contact roll (8) and a substrate fixing base) It exists in the position which becomes 0.1 mm between (4)}. And the terminal part of a non-contact roll (8) is inserted in this hole. The guard (13) is in contact with the upper surface of the substrate fixing base (4) and both end portions of the doctor (7).

(2) Electronic board Electronic board (core) having openings shown in Table 3 using FR-4 double-sided copper-clad laminate (compliant with JIS C6480-1994 “General Rules for Copper-clad Laminates for Printed Wiring Boards”) The substrate was prepared in accordance with the contents described in paragraphs 0013 to 0031 of JP-A-2002-141661.

(3) Filling step A release film (5) {Polyester film of the same size as the electronic substrate: Re-peeling film ST manufactured by Panac Co., Ltd .: thickness 50 μm} is attached to the bottom surface of the electronic substrate, and the concave portion of the fixing base (4) It was fixed by fitting (with the substrate thickness and the release film (5) the same depth as the total thickness) so that the release film (5) was on the bottom (so that the surface of the electronic substrate appeared in the table). .
Next, after placing the electronic substrate filling resin on the end of the electronic substrate (FIG. 4), the angle between the doctor (7) and the electronic substrate surface is set to 15 °, and the vacuum chamber (3) is decompressed to 133 Pa. I made it. Next, the electronic substrate filling resin was filled in the openings of the electronic substrate under the conditions shown in Table 3 {roll moving speed, roll peripheral speed, distance between non-contact roll and electronic substrate (roll interval)} (FIG. 4). ~ 6).
After filling under reduced pressure, the pressure in the vacuum chamber (3) is returned to atmospheric pressure, and the angle between the doctor (7) and the electronic substrate surface is changed to 40 °. The substrate was filled with an electronic substrate filling resin under the same conditions as those under reduced pressure (atmospheric pressure replenishment process FIGS. 4 to 6).

(4) Temporary curing step, polishing step Among the substrates obtained by filling the electronic substrate filling resin as described above, the substrates obtained in Examples 1 to 10 and Comparative Examples 1 to 5 were circulated and heated. By heating in an oven at 130 ° C. for 30 minutes (temporary curing step), a resin-cured substrate was obtained. Similarly, the substrates obtained in Examples 11 to 12 and Comparative Example 6 were irradiated with 1 J / cm ² of ultraviolet rays (temporary curing step) to obtain resin-cured substrates.
After removing the release film (5) attached to the bottom of the substrate from the resin-cured substrate, uniaxial non-woven cloth buff (trade name “IDB-600” manufactured by Ishii Notation Co., Ltd., roughness 320 buff twice, roughness The surface was flattened by using a # 600 buff twice) to obtain a resin-filled substrate.

(5) Evaluation of the number of defective fillings 100 filling points were randomly selected for each filling portion, and the number of defective fillings was evaluated as follows.
Using a tabletop hand cutter (trade name “Hand Cutter PC-300” manufactured by Sanhayato Co., Ltd.), the prepared resin-filled substrate was cut perpendicularly to the substrate surface, and a polishing / polishing machine (trade name “Struers Planopol-3”). ”, Manufactured by Marumoto Kogyo Co., Ltd.), the cut surface was polished to prepare a filling cross section having an opening. Then, this filled cross section was observed with a microscope (magnification 200 times), the openings with unfilled (dents, cavities) were counted, and the total number was shown in Table 1a, Table 1b and Table 2. In addition, the thing with the level | step difference of 10 micrometers or more of the surface of the resin filled and the board | substrate surface around an opening part was made into the dent, and the void and crack with a diameter of 10 micrometers or more were made into the cavity.

  As apparent from Table 1a, Table 1b and Table 2, when the electronic substrate filling resin of the comparative example is used, filling defects frequently occur, whereas in the electronic substrate filling resin of the present invention, the openings are not filled. The resin-filled substrate could be easily produced with almost no (cavities due to dents, voids and cracks).

The resin for filling an electronic board of the present invention fills openings (concave portions and / or through-holes) existing in printed wiring boards (build-up printed wiring boards, multilayer laminated printed wiring boards, double-sided printed wiring boards, etc.) and the like. Suitable for In addition to a printed wiring board, the present invention can also be applied to filling an opening formed in a plate-like material made of metal, stone, glass, concrete and / or plastic.

Claims (5)

A non-contact roll (R) under a pressure of 10 to 10000 Pa and a doctor arranged in contact with or in close proximity to the non-contact roll (R) on the opposite side to the moving direction of the non-contact roll (R) The direction of rotation of the portion on the electronic substrate side with respect to the rotation axis of (R) while linearly moving at a moving speed (i) (mm / sec) in the horizontal direction with respect to the rotation axis of (R) Resin for filling an electronic substrate for the step of filling the opening of the electronic substrate by rotating (R) at a peripheral speed (v) (mm / second) greater than (i) so that is opposite to the moving direction Because
Comprising an inorganic filler (F) and a curable resin (K),
Based on the total weight of the inorganic filler (F) and the curable resin (K), the content of (F) is 55 to 90% by weight, the content of (K) is 10 to 45% by weight,
The inorganic filler (F) comprises a spherical inorganic filler (F1) having a volume average particle diameter of 3 to 8 μm and a non-spherical inorganic filler (F2) having a volume average particle diameter of 0.1 to 3 μm, and the weight of (F) The content of (F1) is 50 to 99% by weight, the content of (F2) is 1 to 50% by weight,
The spherical inorganic filler (F1) is spherical silica and / or spherical metal powder, and the non-spherical inorganic filler (F2) is aluminum oxide surface-treated barium sulfate or aluminum hydroxide surface-treated barium sulfate,
The curable resin (K) comprises bisphenol A type liquid epoxide and / or bisphenol F type liquid epoxide, and a solid curing agent having a volume average particle size of 1 to 8 μm,
All tan δ {loss elastic modulus (G ″) / storage elastic modulus (G ′)} at a frequency of 1 to 10 Hz is 3 to 30, and volatile matter (133 Pa, 80 ° C., 4 hours) is 0.2 weight. % Resin or less for filling an electronic substrate. 2. The resin for filling an electronic substrate according to claim 1, wherein the viscosity (23 ° C., JIS Z8803-1991, 8. Viscosity measurement method using a single cylindrical rotational viscometer) is 200 to 2000 Pa · s. Electronic board filling resin according to claim 1 or 2 cure shrinkage is not more than 2.0% by volume. Resin filling substrate filled with an electronic board for filling resin according to any one of claims 1-3. An electronic device incorporating the resin-filled substrate according to claim 4 .

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