JP6623747B2 - Manufacturing method of wiring board - Google Patents

Description

  The present invention relates to a method for manufacturing a wiring board for mounting a semiconductor chip.

  In recent years, demands for thinner and lighter electronic devices have become stronger, and thinner and higher density wiring boards for mounting semiconductor packages and semiconductor chips have been developed. Therefore, as a printed wiring board used for mounting electronic components, a component built-in substrate in which electronic components are embedded inside a plurality of stacked wiring layers has come to be used. For example, in Patent Literature 1, a through hole for accommodating an electronic component is formed on a core substrate by a known drilling method using a drill or the like, and an adhesive tape is attached to one surface, and the adhesive tape is formed on the adhesive surface. A component built-in substrate manufactured by mounting electronic components is disclosed.

  Recently, with the thinning of wiring boards for mounting semiconductor chips, a compression molding method has been used as a semiconductor chip sealing process instead of the transfer molding method conventionally used (for example, see Patent Reference 2).

International Publication No. 2010/038489 WO 2013/183671

  Further, it has been studied to fabricate a component-embedded substrate by further forming a conductor layer on a substrate in which a semiconductor chip is sealed. However, a substrate sealed by a conventional compression molding method tends to have insufficient adhesive strength with a conductor layer.

  The present invention has been made in view of such circumstances, and an object of the present invention is to provide a method for manufacturing a wiring board for mounting a semiconductor chip having a resin layer having excellent adhesion to a conductor layer.

  As a result of intensive studies to achieve the above object, the present invention forms a resin layer on a substrate when sealing a semiconductor chip by performing compression molding using a release sheet having a resin layer. The present inventors have found a method of manufacturing a wiring board that can perform the above-described steps, and have reached the present invention.

That is, the present invention provides the following aspects.
[1] A method for manufacturing a wiring board for mounting a semiconductor chip by a compression molding method using a first mold having a concave portion and a second mold having a flat surface, wherein a resin layer and a release layer are formed. After the release sheet for compression molding having the support base material in this order is attached to the first mold along the recess so that the support base comes into contact with the first mold, it is sealed on the resin layer of the recess. A step of providing a stopper, a step of attaching a substrate on which a semiconductor chip is mounted to a second mold so that the semiconductor chip faces the recess, and combining the first mold and the second mold. Forming a sealing portion for sealing the semiconductor chip by pressurizing while heating and sealing the sealing material, separating the first mold and the second mold, and removing the resin from the release layer. Removing the layer and transferring the resin layer onto the substrate so as to cover the sealing portion. A method for manufacturing a wiring substrate that.
[2] A method of manufacturing a wiring board for mounting a semiconductor chip by a compression molding method using a first mold having a concave portion and a second mold having a flat surface, wherein a resin layer and a release layer are formed. After attaching a release sheet for compression molding having a support base material in this order to the first mold along the concave portion so that the support base body is in contact with the first mold, the substrate on which the semiconductor chip is mounted A step of applying a sealing material thereon, a step of attaching a substrate on which the semiconductor chip is mounted to a second mold so that the semiconductor chip faces the recess, and a step of attaching the first mold and the second mold Forming a sealing portion for sealing the semiconductor chip by pressurizing while applying heat while curing the sealing material, separating the first mold and the second mold, and releasing the mold. Peel the resin layer from the layer and transfer the resin layer onto the substrate so as to cover the sealing part A method for manufacturing a wiring board comprising that the step.
[3] The method according to [1] or [2], wherein the shape of the sealing material is a granule, a pellet, or a sheet.
[4] The method according to any one of [1] to [3], wherein the thickness of the resin layer is 1 to 10 μm.
[5] The method according to any one of [1] to [4], wherein the resin layer contains a polyfunctional epoxy resin, an epoxy resin curing agent, and a phenolic hydroxyl group-containing polyamide resin.

  According to the present invention, it is possible to provide a method for manufacturing a wiring board for mounting a semiconductor chip having a resin layer having excellent adhesion to a conductor layer.

It is sectional drawing which shows the release sheet | seat which concerns on this embodiment typically. It is sectional drawing which shows typically the manufacturing process of the wiring board which concerns on this embodiment. It is sectional drawing which shows typically the board | substrate to which the resin layer was transferred.

  Hereinafter, embodiments of the present invention will be described in detail. However, the present invention is not limited to the following embodiments.

  In the present specification, the term “step” is included in the term, not only in an independent step but also in a case where the intended action of the step is achieved even if it cannot be clearly distinguished from other steps.

  In the present embodiment, the average thickness of the layer or the film (also referred to as the average value of the thickness) is a value obtained by measuring the thickness of five points of the target layer or the film and giving the arithmetic average value. The thickness of the layer or the film can be measured using a micrometer or the like. In the present embodiment, when the thickness of the layer or the film can be directly measured, the thickness is measured using a micrometer. On the other hand, when measuring the thickness of one layer or the total thickness of a plurality of layers, the thickness may be measured by observing a cross section of the release sheet using an electron microscope.

  The wiring board for mounting a semiconductor chip according to the present embodiment is a manufacturing method for manufacturing a wiring board by a compression molding method using a first mold having a concave portion and a second mold having a flat surface, After attaching a release sheet for compression molding having a resin layer, a release layer and a support base in this order to the first mold along the recess so that the support base is in contact with the first mold, Providing a sealing material on the resin layer of the concave portion, attaching a substrate on which the semiconductor chip is mounted to a second mold so that the semiconductor chip faces the concave portion, A step of forming a sealing portion for sealing the semiconductor chip by applying pressure while heating together with the second mold, and separating the first mold and the second mold. Then, the resin layer is peeled from the release layer, and the resin layer is formed so as to cover the sealing portion. And transferring the above can be prepared by a method comprising a.

  Further, the wiring board for mounting a semiconductor chip according to the present embodiment manufactures a wiring board for mounting a semiconductor chip by a compression molding method using a first mold having a concave portion and a second mold having a flat surface. A compression molding release sheet having a resin layer, a release layer, and a support base material in this order, by pressing the first metal mold along the recess so that the support base material is in contact with the first mold. After attaching to the mold, a step of applying a sealing material on the substrate on which the semiconductor chip is mounted, and a step of attaching the substrate on which the semiconductor chip is mounted to the second mold so that the semiconductor chip faces the concave portion. Forming a sealing portion for sealing the semiconductor chip by hardening the sealing material by applying pressure while heating the first mold and the second mold together; and forming the first mold. And the second mold are separated, and the resin layer is separated from the release layer. Apart, it can be prepared by a method comprising the steps of transferring onto a substrate a resin layer so as to cover the seal portion.

(Release sheet for compression molding)
FIG. 1 is a cross-sectional view schematically illustrating a release sheet for compression molding (hereinafter, abbreviated as “release sheet”) according to the present embodiment. The release sheet 1 has a support substrate 4 having a release layer 3 and a resin layer 2 formed on the release layer 3.

  By performing compression molding using the release sheet 1, the mold can be easily released from the substrate after molding, and the resin layer 2 of the release sheet 1 can be transferred onto the substrate. . In the compression molding, since the release sheet 1 is adsorbed to the mold, the release sheet 1 is required to have excellent followability to the shape of the mold. In the release sheet 1, by using a resin having excellent stretchability as the support base material 4, the followability to the mold can be further improved.

  From the viewpoint of heat resistance, the supporting base material 4 preferably has a melting point equal to or higher than the compression molding temperature (for example, 100 ° C. to 200 ° C.). In addition, when the release sheet 1 is mounted on a mold and during molding, the release sheet 1 is prevented from being broken or the like, and since the formation of wrinkles is suppressed in the sealed portion after molding, The support substrate 4 is preferably selected in consideration of the elastic modulus and the elongation.

  As the support base material 4, a commercially available resin film that has not been subjected to a release treatment can be used. From the viewpoint of heat resistance and elastic modulus at high temperature, polyester is preferable as the resin component constituting the resin film. Examples of the polyester include polyethylene terephthalate, polyethylene naphthalate, polybutylene terephthalate, a copolymer thereof, and a modified resin thereof. The support base material 4 is preferably a polyester film formed by molding a polyester resin into a sheet, and more preferably a biaxially stretched polyester film from the viewpoint of followability to a mold.

  The thickness of the support substrate 4 is not particularly limited, but is preferably 5 μm to 100 μm, more preferably 10 μm to 70 μm, and further preferably 15 μm to 50 μm. When the thickness of the supporting substrate 4 is 5 μm or more, it is excellent in handleability and tends to be less wrinkled, and when the thickness is 100 μm or less, it is excellent in followability to a mold during compression molding. There is a tendency that generation of wrinkles and the like in a sealing portion of a semiconductor chip is suppressed.

  The release layer 3 can be produced, for example, by applying a release agent onto the support substrate 4 and drying it. The release agent is not particularly limited, and can be appropriately selected from release agents used in the art.

  Examples of the release agent include a silicone release agent, a fluorine release agent, a polyolefin release agent, and an alkyd resin release agent. The release agent is preferably a thermosetting type from the viewpoint that a crosslinked structure can be formed in the release layer 3 and migration of the release agent component to the resin layer 2 is easily suppressed. As the thermosetting release agent, those containing an aminoalkyd resin are preferable. Examples of commercially available release agents include “Tesfine 303” and “Tesfine 314” (trade names, manufactured by Hitachi Chemical Co., Ltd.). Lubricants, antistatic agents, and the like can be added to the release agent as necessary.

  The thickness of the release layer 3 is not particularly limited, but is preferably 0.01 μm to 1 μm, and more preferably 0.05 μm to 0.8 μm, from the viewpoint of more sufficient release properties and suppression of wrinkles during molding. More preferably, it is still more preferably 0.1 μm to 0.5 μm.

  In addition, the surface of the supporting base material 4 that is in contact with the mold may be adjusted so as to be easily separated from the mold after compression molding. For example, the surface of the support base 4 that is in contact with the mold side may be subjected to surface processing such as satin finish, or a new release layer may be provided separately from the release layer 3. The material constituting the release layer is not particularly limited as long as the material satisfies heat resistance, releasability from a mold, and the like. In this case, the thickness of the release layer is not particularly limited, but is preferably 0.01 μm to 1 μm. If necessary, a layer such as an anchoring improving layer for the release layer, an antistatic layer, and a coloring layer may be provided between the release layer and the support substrate 4.

  The resin layer 2 is formed on the release layer 3. The resin component contained in the resin layer 2 is not particularly limited, but the resin layer 2 may be, for example, a resin composition containing (A) an epoxy resin, (B) an epoxy resin curing agent, and (C) a phenolic hydroxyl group-containing polyamide resin. Can be formed. By transferring the resin layer 2, the substrate according to the present embodiment exhibits high adhesiveness to the conductor layer.

  Examples of the epoxy resin (A) include phenol novolak type epoxy resin, cresol novolak type epoxy resin, aralkyl type epoxy resin, aralkyl novolak type epoxy resin, naphthalene type epoxy resin, and naphthalene novolak type epoxy resin. These may be used alone or in combination of two or more. From the viewpoint of improving the adhesiveness of the resin layer 2, the epoxy resin (A) preferably contains an aralkyl novolak type epoxy resin having a biphenyl structure. Commercially available aralkyl novolak epoxy resins having a biphenyl structure include, for example, NC-3000 and NC-3000-H manufactured by Nippon Kayaku Co., Ltd.

  The content of the epoxy resin (A) in the resin composition is preferably 20 to 70% by mass based on the total solid content of the resin composition excluding the solvent. Thereby, it becomes easy to achieve both the adhesiveness of the resin layer to the conductor layer and the solder heat resistance.

  (B) As the epoxy resin curing agent, for example, a phenolic resin-based curing agent, an acid anhydride-based curing agent, an amine-based curing agent, a hydrazide-based curing agent, and the like can be used. Examples of the phenolic resin-based curing agent include a novolak-type phenolic resin and a resol-type phenolic resin. Examples of the acid anhydride-based curing agent include phthalic anhydride, benzophenonetetracarboxylic dianhydride, and methylhymic acid. Examples of the amine-based curing agent include dicyandiamide, diaminodiphenylmethane, and guanylurea. Examples of the hydrazide-based curing agent include adipic dihydrazide, sebacic dihydrazide, dodecandiohydrazide, isophthalic dihydrazide, salicylic acid hydrazide, and the like. These may be used alone or in combination of two or more. Among these, from the viewpoint of improving the reliability of the resin layer, it is preferable that the epoxy resin curing agent (B) contains a novolak-type phenol resin.

  The functional group equivalent of (B) the epoxy resin curing agent in the resin composition is preferably 0.5 to 1.5 equivalents to the epoxy group of the (A) epoxy resin, and is preferably 0.7 to 1. The equivalent is more preferably 2 equivalents, and further preferably 0.8 to 1.1 equivalents. Thereby, the adhesiveness of the resin layer to the conductor layer can be easily improved, and further, the glass transition temperature (Tg) of the resin layer can be increased, and the insulating property can be improved.

(B) A reaction accelerator can be used together with the epoxy resin curing agent, if necessary. As the reaction accelerator, for example, various imidazoles and BF ₃ amine complexes which are latent thermosetting agents can be used. In view of storage stability of the resin composition, handleability of the B-stage (semi-cured) resin layer, and solder heat resistance, examples of the reaction accelerator include 2-phenylimidazole and 2-ethyl-4-methylimidazole. Is preferred. When the reaction accelerator is used, the amount is preferably from 0.1 to 8.0 parts by mass, more preferably from 0.2 to 6.0 parts by mass, and more preferably from 0.2 to 6.0 parts by mass, per 100 parts by mass of the epoxy resin. More preferably, the amount is from 0.5 to 5.0 parts by mass. Thereby, the solder heat resistance of the resin layer can be further improved.

  By using (C) a phenolic hydroxyl group-containing polyamide resin, the adhesiveness of the resin layer to the adherend can be further improved. The reason why such an effect is obtained is not necessarily clear, but the phenolic hydroxyl group-containing polyamide resin reacts with the epoxy resin, and it becomes possible to toughen the resin while maintaining good heat resistance of the epoxy resin. Conceivable.

  (C) The phenolic hydroxyl group-containing polyamide resin can be synthesized, for example, by the following method. That is, an equivalent amount of a diamine is added to a dicarboxylic acid component containing a dicarboxylic acid having a phenolic hydroxyl group, and, for example, using a condensing agent in the presence of a phosphite and a pyridine derivative to form N-methyl-2- The condensation reaction is carried out in an organic solvent such as pyrrolidone under heating and stirring under an inert atmosphere such as nitrogen to produce a polyamide resin containing a phenolic hydroxyl group.

  (C) The phenolic hydroxyl group-containing polyamide resin may be a copolymer of a phenolic hydroxyl group-containing polyamide and polybutadiene, or a copolymer of a phenolic hydroxyl group-containing polyamide and poly (butadiene-acrylonitrile). Good. Such a phenolic hydroxyl group-containing polyamide can be synthesized, for example, by the following method. That is, an excess amount of a diamine is added to a dicarboxylic acid component containing a dicarboxylic acid having a phenolic hydroxyl group, and these are added to a N-methyl ester using, for example, a condensing agent in the presence of a phosphite and a pyridine derivative. -2- Condensation reaction is carried out in an organic solvent such as pyrrolidone while heating and stirring under an inert atmosphere such as nitrogen to produce a polyamide oligomer having an amino group at both terminals. Next, polybutadiene or poly (butadiene-acrylonitrile) having carboxyl groups at both ends is added and polycondensed with the above polyamide oligomer, whereby the phenolic hydroxyl group-containing polyamide is co-polymerized with polybutadiene or poly (butadiene-acrylonitrile) Coalescence can be obtained. In addition, a dicarboxylic acid component having a phenolic hydroxyl group is used in excess of a diamine to synthesize a polyamide oligomer having a carboxylic acid group at both terminals, and polybutadiene or poly () having an amino group at both terminals. (Butadiene-acrylonitrile). Furthermore, it is also possible to modify the terminal of these polyamide, polybutadiene or poly (butadiene-acrylonitrile) to cause a reaction. In this case, for example, one may be modified with a vinyl group and the other with a -NH or -SH group. In the step of synthesizing the phenolic hydroxyl group-containing polyamide, a compound having a phenolic hydroxyl group in part or all of the diamine may be used.

  Polybutadiene having various functional groups at both ends is commercially available, for example, as Hycar CTB from Goodrich, and poly (butadiene-acrylonitrile) is commercially available, for example, as Hycar CTBN from Goodrich. These can be used to react with the above-mentioned phenolic hydroxyl group-containing polyamide oligomer.

  Examples of the dicarboxylic acid having a phenolic hydroxyl group include hydroxyisophthalic acid such as 5-hydroxyisophthalic acid and 4-hydroxyisophthalic acid, hydroxyphthalic acid such as 2-hydroxyphthalic acid and 3-hydroxyphthalic acid, and 2-hydroxyterephthalic acid. And hydroxyterephthalic acid such as an acid.

  (C) The dicarboxylic acid component used when synthesizing the phenolic hydroxyl group-containing polyamide resin may contain a dicarboxylic acid having no phenolic hydroxyl group. Examples of the dicarboxylic acid having no phenolic hydroxyl group include phthalic acid, isophthalic acid, terephthalic acid, dicarboxylic naphthalene, succinic acid, fumaric acid, glutaric acid, adipic acid, 1,3-cyclohexanedicarboxylic acid, and 4,4 ′ -Diphenyldicarboxylic acid, 3,3'-methylene dibenzoic acid, and the like.

  (C) The dicarboxylic acid used when synthesizing the phenolic hydroxyl group-containing polyamide resin may be used alone or in combination of two or more.

  Examples of the diamine having a phenolic hydroxyl group include, for example, 3,3'-diamine-4,4'-dihydroxyphenylmethane, 2,2-bis (3-amino-4-hydroxyphenyl) hexafluoropropane, 2,2- Bis (3-amino-4-hydroxyphenyl) difluoromethane, 3,4-diamino-1,5-benzenediol, 3,3′-dihydroxy-4,4′-diaminobisphenyl, 3,3′-diamino-4 , 4'-Dihydroxybiphenyl, 2,2-bis (3-amino-4-hydroxyphenyl) ketone, 2,2-bis (3-amino-4-hydroxyphenyl) sulfide, 2,2-bis (3-amino -4-hydroxyphenyl) ether, 2,2-bis (3-amino-4-hydroxyphenyl) sulfone, 2,2-bis (3-amino 4-hydroxyphenyl) propane, 2,2-bis (3-hydroxy-4-aminophenyl) propane, 2,2-bis (3-hydroxy-4-aminophenyl) methane, and the like.

  Examples of the diamine having no phenolic hydroxyl group include, for example, 3,3′-diaminodiphenyl ether, 3,4′-diaminodiphenyl ether, 4,4′-diaminodiphenyl ether, diaminonaphthalene, piperazine, hexanetylenediamine, tetramethylenediamine, m-xylenediamine, 4,4'-diaminodiphenylmethane, 4,4'-diaminobenzophenone, 2,2'-bis (4-aminophenyl) propane, 3,3'-diaminodiphenylsulfone, 3,3'-diamino Diphenyl, 3,3 ′, 5,5′-tetraethyl-4,4′-diaminodiphenylmethane and the like. Among these, for example, 3,4'-diaminodiphenyl ether and 3,3 ', 5,5'-tetraethyl-4,4'-diaminodiphenylmethane are preferred.

  Commercially available phenolic hydroxyl group-containing polybutadiene-modified polyamide resins include, for example, BPAM-155 manufactured by Nippon Kayaku Co., Ltd.

  The amount of the (C) phenolic hydroxyl group-containing polyamide resin contained in the resin composition is based on 100 parts by mass of the total of (A) the epoxy resin, (B) the epoxy resin curing agent, and (C) the phenolic hydroxyl group-containing polyamide resin. , Preferably 5 to 50 parts by mass, more preferably 10 to 40 parts by mass, even more preferably 15 to 30 parts by mass. (C) When the amount of the phenolic hydroxyl group-containing polyamide resin is 5 parts by mass or more, the toughness of the resin layer tends to be improved, and good adhesion to the conductor layer tends to be easily obtained. , Good heat resistance and chemical resistance tend to be easily obtained.

  The resin composition may contain (D) an inorganic filler. That is, the resin layer according to the present embodiment can further include (D) an inorganic filler. As the inorganic filler, for example, silica, alumina, barium sulfate, talc, clay, mica powder, aluminum hydroxide, magnesium hydroxide, calcium carbonate, magnesium carbonate, magnesium oxide, boron nitride, aluminum borate, barium titanate, Examples include strontium titanate, calcium titanate, bismuth titanate, titanium oxide, barium zirconate, and calcium zirconate. Among these, fumed silica and alumina are preferred from the viewpoint of a low coefficient of thermal expansion. These inorganic fillers may be used alone or in combination of two or more.

The inorganic filler can be appropriately selected according to the purpose. From the viewpoint of forming fine wiring on the resin layer, for example, the specific surface area is preferably 20 m ² / g or more. The specific surface area of the inorganic filler can be determined by a measurement method usually performed by those skilled in the art, and for example, can be measured by a BET method. The BET method is a method in which molecules whose adsorption area is known are adsorbed on the surface of powder particles at the temperature of liquid nitrogen, and the specific surface area of the sample is determined from the amount. In the specific surface area analysis, the BET method using an inert gas such as nitrogen is most often used.

  The inorganic filler may be surface-treated with a surface treating agent such as a silane coupling agent to improve moisture resistance, or may be subjected to hydrophobic treatment to improve dispersibility.

  The inorganic filler may be mixed by a known kneading and dispersing method such as a kneader, a ball mill, a bead mill, a three-roll mill, or a nanomizer for the purpose of enhancing dispersibility in the resin composition.

  Various additives such as a thixotropic agent, a surfactant, and a coupling agent, which are commonly used in a resin composition, may be appropriately added to the resin composition. When these additives are blended, the resin composition can be obtained by stirring sufficiently, and then allowing the mixture to stand until bubbles disappear.

  It is preferable in terms of workability that the resin composition is mixed and diluted or dispersed in a solvent and used in the form of a varnish. Examples of the solvent include methyl ethyl ketone, xylene, toluene, acetone, ethylene glycol monoethyl ether, cyclohexanone, ethyl ethoxypropionate, N, N-dimethylformamide, N, N-dimethylacetamide and the like. These solvents may be used alone or in combination of two or more.

  The compounding amount of the solvent is appropriately adjusted according to equipment for forming a resin layer using the resin composition. For example, the solid content of the resin composition excluding the solvent is 5 to 50% by mass in the varnish. It is preferable to adjust the amount of the solvent used.

  The method for preparing the resin composition is not particularly limited, and a conventionally known preparation method can be used. For example, (A) an epoxy resin, (B) an epoxy resin curing agent and (C) a phenolic hydroxyl group-containing polyamide resin were added to a solvent, and various additional components such as a reaction accelerator used as needed were added. After that, it is prepared as a varnish by mixing and stirring using various mixers such as an ultrasonic dispersion system, a high-pressure collision dispersion system, a high-speed rotation dispersion system, a bead mill system, a high-speed shear dispersion system, and a rotation revolution dispersion system. be able to.

  The resin layer 2 is formed, for example, by applying a resin composition (varnish) on the release layer 3 and drying at a temperature of about 60 to 200 ° C. for about 1 to 20 minutes. When the drying temperature is 60 ° C. or more and the drying time is 1 minute or more, the drying proceeds sufficiently and the generation of voids in the resin layer 2 can be suppressed. On the other hand, when the drying temperature is 180 ° C. or less and the drying time is 10 minutes or less, it is possible to suppress the progress of the drying excessively and the reduction of the resin flow amount. Note that, here, the solvent in the varnish has been volatilized by drying, and the resin layer is in the B-stage state in which the curing treatment has not been performed.

  The method for applying the resin composition is not particularly limited, and for example, a die coater, a gravure coater, a comma coater, or the like can be used. From the viewpoint of reducing the thickness of the resin layer 2, it is preferable to use a die coater or a gravure coater.

  The thickness of the resin layer 2 is appropriately selected depending on the purpose, but is preferably 1 μm to 10 μm, more preferably 1 μm to 8 μm, and still more preferably 1 μm to 5 μm, from the viewpoint of better adhesion and thinning of the substrate.

[Method of Manufacturing Wiring Board for Mounting Semiconductor Chip]
<Step 1>
FIG. 2 is a cross-sectional view schematically showing a manufacturing process of the wiring board according to the present embodiment using the release sheet 1. By using the release sheet 1, the sealing portion 7 a for sealing the semiconductor chip 9 mounted on the substrate 5 can be formed, and the resin layer 2 can be transferred to the substrate 5. Hereinafter, a method for manufacturing the wiring board according to the present embodiment will be described.

  The mold used for the compression molding method includes a first mold 24 and a second mold 22. The second mold 22 is a portion where the substrate 5 is arranged, and has a flat surface. The first mold 24 has a concave portion at a portion facing the semiconductor chip 9 mounted on the substrate 5.

  First, as shown in FIG. 2A, the release sheet 1 is attached to the first mold 24 along the recess so that the support base material 4 comes into contact with the first mold 24. The first mold 24 is provided with a suction mechanism (vacuum suction or the like), and the release sheet 1 is sucked and held by the first mold 24. Next, the sealing material 7 is provided on the resin layer 2 in the concave portion of the first mold 24. On the other hand, the substrate 5 is mounted on the second mold 22 such that the semiconductor chip 9 faces the concave portion of the first mold 24. Note that the sealing material 7 may be provided on the semiconductor chip 9.

  Subsequently, as shown in FIG. 2B, the first mold 24 and the second mold 22 are combined, and the sealing material 7 is compressed and heated. As a result, the sealing material 7 is cured into a shape along the concave portion of the first mold 24, and the semiconductor chip 9 is sealed. From the viewpoint of workability, the mold temperature during compression molding is preferably 100 to 200 ° C., the molding pressure is 0.5 to 10 MPa, and the molding time is preferably 60 to 600 seconds.

  After the sealing material 7 is cured to form the sealing portion 7a, the second mold 22 is separated from the first mold 24, as shown in FIG. At this time, the resin layer 2 is separated from the release layer 3 and adheres to the sealing portion 7a and the substrate 5 and is transferred. In the above process, the sealing of the semiconductor chip and the formation of the resin layer on the substrate can be performed at the same time, so that the wiring substrate for mounting the semiconductor chip can be manufactured more easily than in the past.

(Sealing material)
As a sealing material used in the present embodiment, a general sealing material for compression molding can be used, and it is preferable to include a thermosetting resin and an inorganic filler.

  The shape of the sealing material is not particularly limited, and any of a granular shape, a pellet shape, and a sheet shape can be used.

  There is no particular limitation on the thermosetting resin, for example, epoxy resin, phenol resin, unsaturated imide resin, cyanate resin, isocyanate resin, benzoxazine resin, oxetane resin, amino resin, unsaturated polyester resin, allyl resin, dicyclo resin Examples include a pentadiene resin, a silicone resin, a triazine resin, and a melamine resin. An epoxy resin or a cyanate resin is preferable in terms of excellent moldability and electrical insulation.

  Examples of the epoxy resin include bisphenol A epoxy resin, bisphenol F epoxy resin, bisphenol S epoxy resin, phenol novolak epoxy resin, cresol novolak epoxy resin, bisphenol A novolak epoxy resin, and bisphenol F novolak epoxy resin. , Stilbene type epoxy resin, triazine skeleton containing epoxy resin, fluorene skeleton containing epoxy resin, triphenol phenol methane type epoxy resin, biphenyl type epoxy resin, xylylene type epoxy resin, biphenyl aralkyl type epoxy resin, naphthalene type epoxy resin, dicyclopentadiene Epoxy resin, alicyclic epoxy resin, polyfunctional aromatic phenols and diglycidyl ether compounds of polycyclic aromatics such as anthracene Phosphorus-containing epoxy resins. Among these, biphenyl aralkyl type epoxy resins and naphthalene type epoxy resins are preferred from the viewpoint of heat resistance and flame retardancy. These can be used alone or in combination of two or more.

  Examples of the cyanate resin include a novolak type cyanate resin, a bisphenol A type cyanate resin, a bisphenol E type cyanate resin, a tetramethylbisphenol F type cyanate resin, and a prepolymer in which a part of these resins is triazine. Among these, a novolak type cyanate resin is preferred from the viewpoint of heat resistance and flame retardancy. These cyanate resins can be used alone or in combination of two or more.

  The content of the thermosetting resin contained in the sealing material is preferably 20 to 80% by mass, more preferably 40 to 80% by mass, and further preferably 50 to 80% by mass, based on the resin component in the sealing material. Preferably, it is even more preferably 60 to 75% by mass.

  Examples of the inorganic filler include silica, alumina, talc, mica, aluminum hydroxide, magnesium hydroxide, calcium carbonate, aluminum borate, and borosilicate glass. Among these, silica is preferable from the viewpoint of low thermal expansion. Further, spherical amorphous silica having a very low thermal expansion coefficient of about 0.6 ppm / K and a small decrease in fluidity when highly filled into a resin is preferred. More preferred.

  The spherical amorphous silica preferably has a cumulative 50% particle diameter of 0.01 to 10 μm, and more preferably 0.03 to 5 μm. Here, the cumulative 50% particle size is a particle size at a point corresponding to exactly 50% volume when a cumulative frequency distribution curve based on the particle size is determined with the total volume of the powder being 100%. Can be measured with a particle size distribution measuring device or the like using

  The content of the inorganic filler in the sealing material is preferably from 5 to 75% by volume, more preferably from 15 to 70% by volume, even more preferably from 30 to 70% by volume of the total amount of the sealing material. When the content of the inorganic filler is 5% by volume or more, the effect of reducing the coefficient of thermal expansion becomes sufficient, and when it is 75% by volume or less, the fluidity increases and the moldability becomes better.

  When expressed by mass%, the content of the inorganic filler in the sealing material is preferably from 8 to 85 mass%, more preferably from 24 to 82 mass%, and more preferably from 44 to 82 mass%. Is more preferable.

In addition, by using a nanofiller having an average primary particle size of 1 μm or less as the inorganic filler, the surface smoothness can be improved. The nanofiller preferably has a specific surface area of 20 m ² / g or more, and from the viewpoint of reducing the surface shape after the roughening treatment in the plating process, the average primary particle diameter is preferably 100 nm or less. This specific surface area can be measured by the BET method. Here, the “average primary particle size” refers not to the average particle size of aggregated particles, that is, the average particle size of a non-aggregated single substance, but to the secondary particle size. The average primary particle size can be determined by, for example, measuring with a laser diffraction type particle size distribution meter. Fumed silica is preferred as such an inorganic filler.

  The inorganic filler may be treated with a surface treatment agent such as a silane coupling agent to improve the moisture resistance of the sealing material, or may be subjected to a hydrophobic treatment to improve the dispersibility.

  FIG. 3 is a cross-sectional view schematically showing the substrate 5 on which the sealing layer 7a is formed and the resin layer 2 is transferred by the process shown in FIG. The sealing portion 7a is provided so as to cover the entire semiconductor chip 9, and the resin layer 2 is provided on the substrate 5 so as to cover the sealing portion 7a.

<Step 2>
The substrate shown in FIG. 3 may be subjected to a step of forming a via in the resin layer 2 or the substrate 5 as necessary. Thereby, a via hole or the like can be formed in the resin layer 2. A method for manufacturing a via is generally used in a manufacturing process of a wiring board. The via hole is provided for electrical connection between layers, and can be formed by a known method using a drill, laser, plasma, or the like in consideration of the characteristics of the resin layer.

  Examples of the laser light source include a carbon dioxide laser, a YAG laser, and an excimer laser. Among them, a carbon dioxide laser is preferred from the viewpoint of excellent processing speed and cost.

  After forming the vias and before forming the conductor layer on the resin layer, if necessary, as a pre-treatment of the semi-additive method, the surface of the resin layer is formed for the purpose of improving the adhesive force with the conductor layer. A step of roughening (desmearing step) may be further performed. The method of roughening the resin layer is not particularly limited, and examples thereof include a UV treatment, a corona discharge treatment, a polishing treatment, and an etching treatment.

  Examples of the roughening solution used for the etching treatment include oxidizing roughening solutions such as a chrome / sulfuric acid roughening solution, an alkali permanganate roughening solution, a sodium fluoride / chromium / sulfuric acid roughening solution, and a borofluoric acid roughening solution. Liquids can be used.

  The surface roughness (Ra) of the resin layer after the desmear treatment step is preferably 0.3 μm or less, more preferably 0.2 μm or less, and further preferably 0.15 μm or less. When the surface roughness (Ra) is 0.3 μm or less, it becomes easy to cope with high-density wiring. The lower limit of the surface roughness (Ra) is not particularly limited, but may be, for example, about 0.01 μm. The surface roughness (Ra) can be measured, for example, using a surface shape measuring device Wyko NT9100 (trade name) manufactured by Veeco. The measurement range is, for example, a range of 0.120 mm × 0.095 mm.

<Step 3>
If necessary, a conductor layer can be formed on the resin layer of the substrate on which the via formation and desmear processing steps have been performed. As a method of forming the conductor layer on the resin layer, for example, a semi-additive method of forming a circuit using a plating process can be used. The formation of the conductor layer can be performed, for example, by the following procedure.

  First, after performing a plating catalyst application treatment for adhering palladium to the resin layer whose surface may be roughened, an electroless plating treatment is performed, and a thickness of 0.3 to 1.5 μm is formed on the resin layer. Of an electroless plating layer (conductor layer). The plating catalyst application treatment is performed by immersing the insulating film with the resin layer in a palladium chloride-based plating catalyst solution, and the electroless plating treatment is performed by immersion in the electroless plating solution. As the electroless plating solution, a known electroless plating solution can be used, and it is not particularly limited, but it is preferable to use an electroless copper plating solution.

  Next, after a pattern of a plating resist is formed on the electroless plating layer, electrolytic plating is performed to form an electrolytic plating layer (conductor layer) having a desired thickness at a desired position. Thereafter, the plating resist is peeled off, and unnecessary electroless plating layers are removed by etching. As a result, a conductor layer including the electroless plating layer and the electrolytic plating layer is formed on the resin layer. As the plating resist, a known plating resist can be used, and there is no particular limitation. The electrolytic plating treatment can be performed according to a known method, and is not particularly limited, but it is preferable to use an electrolytic copper plating solution as the electrolytic plating solution. Since the resin layer according to the present embodiment has excellent adhesion to the conductor layer, a pattern can be formed even if the conductor layer is fine. Specifically, it can be suitably used for forming a wiring having a line and space (L / S) of 10 μm / 10 μm or less, and particularly preferably for forming a wiring having a line and space (L / S) of 5 μm / 5 μm or less. .

  The preferred embodiments of the present invention have been described above, but these are examples for describing the present invention, and are not intended to limit the scope of the present invention only to these embodiments. The present invention can be implemented in various modes different from the above-described embodiment without departing from the gist thereof.

  Hereinafter, the present invention will be specifically described with reference to examples. However, the present invention is not limited to these examples.

(Preparation of resin composition)
After mixing 1.8 g of phenolic hydroxyl group-containing polybutadiene-modified polyamide (trade name “BPAM-155” manufactured by Nippon Kayaku Co., Ltd.) and 15.9 g of N, N-dimethylacetamide (DMAc), biphenylaralkyl novolak epoxy 5.0 g of resin (manufactured by Nippon Kayaku Co., Ltd., trade name "NC-3000-H"), 2.1 g of cresol novolac type phenol resin (manufactured by DIC Corporation, trade name "KA1165") and 2-phenylimidazole (Shikoku) 0.050 g of Kasei Kogyo Co., Ltd., trade name “2PZ”) was added, and diluted with a mixed solvent consisting of DMAc and methyl ethyl ketone, and 0.50 g of silica filler (trade name “AEROSIL R972”, manufactured by Nippon Aerosil Co., Ltd.) was added. The added solution was added to a dispersing machine (Yoshida Kikai Kogyo Co., Ltd. Using a "Nanomizer"), a uniform resin composition varnish A (solid concentration: about 25% by mass) was obtained.

(Example 1)
(1) Preparation of Release Sheet for Compression Molding After corona treatment of a 25 μm-thick biaxially oriented polyethylene terephthalate film (manufactured by Unitika Ltd., trade name “S-25”), an amino alkyd resin (manufactured by Hitachi Chemical Co., Ltd.) The product was diluted with methyl ethyl ketone and toluene (mass ratio of methyl ethyl ketone: toluene = 3: 7) to 2.5% by mass and prepared using a die coater. After drying at 40 ° C. for 40 seconds, a release substrate having a release layer having a thickness of 0.2 μm was obtained. Next, the varnish A was applied to the surface of the release layer of the release substrate, and dried at 180 ° C. for 10 minutes to produce a release sheet for compression molding having a resin layer having a thickness of 3 μm.

(2) Production of Evaluation Substrate As shown in FIG. 2A, the substrate 5 on which the semiconductor chip 9 was mounted was attached to a second mold 22 for compression molding. Next, the release sheet 1 obtained in the above (1) is arranged in a first mold 24 for compression molding and fixed by vacuum, and then the resin layer 2 in the concave portion of the first mold 24 is formed. A sealing material (trade name “CEL-9750ZHF10” manufactured by Hitachi Chemical Co., Ltd.) was placed on the top. Subsequently, as shown in FIG. 2B, the second mold 22 and the first mold 24 are combined and clamped, and the mold temperature is 180 ° C., the molding pressure is 6.86 MPa (70 kgf / cm). ² ) Under the condition of a molding time of 90 seconds, the sealing material 7 was cured and molded. Thereafter, as shown in FIG. 2C, the second die 22 is separated from the first die 24, and the release layer 3 is separated from the resin layer 2 to seal the semiconductor chip 9. Then, a semiconductor package substrate in which the resin layer 2 was transferred onto the substrate 5 was obtained. Thereafter, the semiconductor package substrate was heat-treated at 180 ° C. for 3 hours to produce a substrate for evaluation.

(3) Production of via Using a CO ₂ laser processing machine (trade name “LCO-1B21” manufactured by Hitachi Via Mechanics Co., Ltd.) under the conditions of a beam diameter of 80 μm, a frequency of 500 Hz, a pulse width of 5 μsec, and a number of shots of 7, Vias were formed in the evaluation substrate prepared in (2).

(4) Desmear treatment The substrate having the via obtained in (3) was immersed in an aqueous solution containing diethylene glycol monobutyl ether (200 mL / L) and NaOH (5 g / L) as swelling liquid at 80 ° C. for 5 minutes. Thereafter, the resultant was immersed in an aqueous solution containing KMnO ₄ (60 g / L) and NaOH (40 g / L) as a roughening solution at 80 ° C. for 10 minutes. Subsequently, it was neutralized by immersion treatment in an aqueous solution containing SnCl ₂ (30 g / L) as a neutralizing solution and H ₂ SO 4 (300 mL / L) having a concentration of 98% by mass at room temperature for 5 minutes.

(5) Electroless plating and electrolytic plating As a pretreatment for electroless plating, the substrate obtained in the above (4) was treated at 60 ° C. with a conditioner liquid “CLC-601” (trade name, manufactured by Hitachi Chemical Co., Ltd.). For 5 minutes, washed with water, and immersed in a pre-dip solution “PD-201” (trade name, manufactured by Hitachi Chemical Co., Ltd.) at room temperature for 2 minutes. Next, after immersion treatment at room temperature for 10 minutes in a catalyst for electroless plating “HS-202B” (trade name, manufactured by Hitachi Chemical Co., Ltd.) containing PdCl ₂ , washing with water, and an electroless copper plating solution “CUST” -201 plating solution "(trade name, manufactured by Hitachi Chemical Co., Ltd.) at room temperature for 15 minutes, followed by copper sulfate electrolytic plating. Thereafter, an annealing treatment was performed at 170 ° C. for 30 minutes to produce a substrate with a conductor layer in which a conductor layer having a thickness of 30 μm was formed on the resin layer.

(Comparative Example 1)
Except for using a corona-treated biaxially stretched polyethylene terephthalate film having a thickness of 25 μm (product name “S-25” manufactured by Unitika Ltd.) instead of the compression-molding release sheet prepared in (1) of Example 1. The same operation as in Example 1 was carried out, and a conductor layer having a thickness of 30 μm was formed directly on the substrate without providing a resin layer, thereby producing a substrate with a conductor layer.

[Plating ability]
The plating abilities of the substrates with the conductor layers produced in the examples and comparative examples were visually evaluated according to the following criteria.
：: A glossy plated copper surface was observed on the entire surface of the substrate.
×: A surface to which plated copper was not adhered to a part of the substrate was observed.

[Adhesive strength of conductor layer / resin layer]
A part of the conductor layer of the substrate with a conductor layer manufactured in Example 1 was etched to form a part having a width of 10 mm and a length of 100 mm, and one end of the part was peeled off at the interface between the conductor layer and the resin layer, and a gripper was obtained. And the load when peeled off at room temperature at a pulling speed of about 50 mm / min in the vertical direction was measured.

[Surface roughness (Ra) measurement]
The conductor layer of the substrate with a conductor layer produced in each of the examples and the comparative examples was removed by etching, and the surface roughness (Ra) of the exposed resin layer surface was measured with a surface shape measuring device (Veeco, trade name “Wyko NT9100”). )).

  From Table 1, it can be confirmed that the board of Example 1 manufactured by the method for manufacturing a wiring board for mounting a semiconductor chip of the present invention has excellent adhesion to the conductor layer. On the other hand, since the substrate of Comparative Example 1 did not have a resin layer, it was difficult to form a plating, and a conductor layer could not be formed.

  DESCRIPTION OF SYMBOLS 1 ... Release sheet, 2 ... Resin layer, 3 ... Release layer, 4 ... Support base material, 5 ... Substrate, 7 ... Sealing material, 7a ... Sealing part, 9 ... Semiconductor chip, 22 ... Second gold Mold, 24 ... First mold.

Claims (5)

A method for producing a wiring board for mounting a semiconductor chip by a compression molding method using a first mold having a concave portion and a second mold having a flat surface,
A compression-molding release sheet having a resin layer, a release layer, and a support base material in this order is provided on the first mold along the recess so that the support base material is in contact with the first mold. After mounting, a step of applying a sealing material on the resin layer of the concave portion,
Attaching a substrate on which a semiconductor chip is mounted to the second mold so that the semiconductor chip faces the concave portion;
Forming a sealing portion for sealing the semiconductor chip by hardening the sealing material by applying pressure while heating the first mold and the second mold together; and
Separating the first mold and the second mold, separating the resin layer from the release layer, and transferring the resin layer onto the substrate so as to cover the sealing portion. When,
Equipped with a,
A method for manufacturing a wiring board, wherein the supporting base material is a biaxially stretched polyester film . A method for producing a wiring board for mounting a semiconductor chip by a compression molding method using a first mold having a concave portion and a second mold having a flat surface,
A compression-molding release sheet having a resin layer, a release layer, and a support base material in this order is provided on the first mold along the recess so that the support base material is in contact with the first mold. After mounting, a step of applying a sealing material on the substrate on which the semiconductor chip is mounted,
Attaching the substrate on which the semiconductor chip is mounted to the second mold so that the semiconductor chip faces the concave portion;
Forming a sealing portion for sealing the semiconductor chip by hardening the sealing material by applying pressure while heating the first mold and the second mold together; and
Separating the first mold and the second mold, separating the resin layer from the release layer, and transferring the resin layer onto the substrate so as to cover the sealing portion. When,
Equipped with a,
A method for manufacturing a wiring board, wherein the supporting base material is a biaxially stretched polyester film .   The method according to claim 1, wherein the shape of the sealing material is a granular shape, a pellet shape, or a sheet shape.   The method according to claim 1, wherein a thickness of the resin layer is 1 to 10 μm.   The method according to any one of claims 1 to 4, wherein the resin layer includes an epoxy resin, an epoxy resin curing agent, and a phenolic hydroxyl group-containing polyamide resin.

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