JP2005183599A - B stage resin composition sheet and method of manufacturing printed circuit substrate for mounting flip chip using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain a printed circuit substrate for mounting a flip chip which can be mounted on the rear surface of a semiconductor chip without manufacturing a bump, and to obtain a B stage resin composition sheet suitable for the same. <P>SOLUTION: The B stage resin composition sheet with a copper foil includes a first resin composition layer b made of a thermoplastic resin composition formed on one side surface of the copper foil a and a second resin composition layer c made of a thermosetting resin composition on the first resin composition layer b. The B stage resin composition sheet is disposed oppositely at least on the semiconductor chip mounting surface of a substrate e on which a conductor circuit d is formed, heated and cured to a substrate for mounting the semiconductor chip. A blind via hole g and/or a through hole u are formed in the semiconductor chip mounting part, and then copper plated to fill the copper plate in the hole. A front layer copper foil and/or copper plating part is etched to the surface of the first resin composition layer. Then, the first resin composition layer is dissolved and removed to the surface of the second resin composition layer with a chemical liquid which does not dissolve the copper plating, and the distal end of the copper plating filling part is projected from the surface of the second resin composition layer. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a B-stage resin composition sheet for lamination for a printed wiring board, and a method for producing a printed wiring board for flip chip mounting using the B-stage resin composition sheet. The B-stage resin composition sheet of the present invention can be used as a sheet for general build-up lamination, but has a structure in which bumps for semiconductor chip mounting connection are formed on the printed wiring board side. This printed wiring board is suitable for a small, light and high density semiconductor plastic package.

  In recent years, high-density printed wiring boards have come to be used in electronic devices that are becoming smaller, thinner, and lighter. The method for mounting and connecting a semiconductor chip to a printed wiring board is flipped from the wire bonding method. It is becoming a chip system. This flip chip is a semiconductor chip with solder bumps etc. on the back side, and this is mounted and connected by melting the bump metal on the printed wiring board on which the circuit for bump connection is formed, and the semiconductor chip and printed wiring with underfill resin It has a structure that fills the gap between the plates (see, for example, Patent Documents 1 to 3). In this case, the surface of the printed wiring board on which the flip chip is mounted is generally coated with a UV selective thermosetting resist, but the surface obtained by applying, exposing and developing the UV selective thermosetting resist has large irregularities. For this reason, when the semiconductor chip is filled with the underfill resin after being mounted and connected, there is a problem that unfilled portions are generated and the heat resistance after moisture absorption is lowered. Further, since the distance between the bump connection circuits is narrow, the UV selective thermosetting resist has a problem that the electrical reliability such as migration resistance is inferior and needs to be improved. Furthermore, since bonding metals such as solder bumps are bonded in advance to the flip chip, strictness is required, and there are problems such as many defects during production.

JP 2001-007478 Japanese Patent Laid-Open No. 2001-111228 JP 2001-111235 A

  The present invention is capable of mounting and connecting a semiconductor chip to a printed wiring board without adhering a connecting metal such as a solder bump to the flip chip, and the surface of the printed wiring board on which the semiconductor chip is mounted has a coating resin surface. The present invention provides a method for producing a smooth printed circuit board for mounting on a flip chip that is excellent in heat resistance and reliability, and provides a B-stage resin composition sheet suitable for this production method.

  In the present invention, a first resin composition layer made of a thermoplastic resin composition is formed on one surface of a copper foil or a release film, and a second resin made of a thermosetting resin composition is formed on the resin composition layer. The present invention relates to a B-stage resin composition sheet with a copper foil or a release film on which a composition layer is formed. Preferably, the thickness of the first resin composition layer is 1 to 10 μm, more preferably, the second The resin composition layer is a B-stage resin composition sheet with a copper foil or a release film, which is a resin composition having a base material reinforced and containing a cyanate ester resin as an essential component. (1) The second resin composition layer surface of the B-stage resin composition sheet is disposed to face at least the semiconductor chip mounting surface of the substrate on which the conductor circuit is formed, and is heated and cured to mount the semiconductor chip. (2) After forming blind via holes and / or through holes in the semiconductor chip mounting portion of the semiconductor chip mounting substrate, copper plating is performed to fill the hole with copper plating, and (3) surface copper foil And / or after the copper plating portion is planarly etched in the thickness direction to the surface of the first resin composition layer, (4) the second resin composition is formed with a chemical solution that does not dissolve the copper plating. A method for producing a printed circuit board for mounting on a flip chip, characterized in that it is dissolved and removed to the surface of the physical layer, and the tip of the copper plating filling portion protrudes from the surface of the second resin composition layer, preferably the step (2) Later, the copper mesh The surface is polished to smooth the surface, and after the step (4), (5) the exposed tip portion of the copper plating filling portion is covered with a protective metal, and the tip portion of the coated copper plating filling portion is coated with This is a manufacturing method for attaching a bump metal, and more preferably a method for manufacturing a flip-chip-mounted printed wiring board in which the second resin composition is a resin composition containing a cyanate ester resin as an essential component.

  The present invention eliminates the trouble of forming bumps on the semiconductor chip by forming bumps for connecting the semiconductor chip on the printed wiring board side, not on the semiconductor chip side. A printed wiring board for chip mounting can be manufactured. Furthermore, since the resin composition surface on the semiconductor chip mounting surface of the printed wiring board becomes smooth, there is no occurrence of poor filling of the underfill resin after the semiconductor chip mounting connection, and as a coating resin for the second resin composition layer, cyanic acid is used. By using the ester resin composition, a product excellent in heat resistance, electrical reliability, etc. was obtained, and a very useful printed wiring board for flip chip mounting, which will become increasingly dense in the future, was obtained. .

  In the B-stage resin composition sheet of the present invention, a first resin composition layer made of a thermoplastic resin composition is formed on one side of a copper foil or a release film, and a thermosetting resin is formed on the resin composition layer. A B-stage resin composition sheet with a copper foil or a release film on which a second resin composition layer made of the composition is formed, and can be used as a B-stage resin composition sheet for general build-up lamination, It is preferable to use when manufacturing a flip chip mounting printed wiring board having a structure in which bumps for mounting and mounting semiconductor chips are formed on the printed wiring board side.

  The B-stage resin composition sheet with a copper foil or a release film used in the present invention has a first composition layer made of a thermoplastic resin composition formed on one side of the copper foil or the release film. It will not specifically limit if it is a copper foil in which the 2nd resin composition layer which consists of a thermosetting resin composition was formed, or a B stage resin composition sheet with a release film.

  The thermoplastic resin composition used for the first resin composition layer of the copper foil or the B-stage resin composition sheet with a release film is not particularly limited, but those having a softening temperature of 180 ° C. or higher are preferably used. Specifically, polyphenylene ether, polysulfone, polyether sulfone, polycarbonate, polyphenylene sulfide, soluble polyimide resin, liquid crystal polymer, and the like and their known modified products can be used. One or more of these are appropriately selected and used depending on the application. These thermoplastic resin compositions may be added with various known additives and known plating adhesion strength improving metals such as palladium in order to improve the adhesion of copper plating.

  The copper foil on which the first resin composition layer of the B-stage resin composition sheet with a copper foil or a release film is formed is not particularly limited as long as it is a known copper foil used for a printed wiring board, but preferably Electrolytic copper foil, rolled copper foil, and these copper alloys are used. The surface of the copper foil may be smooth or uneven, as long as the adhesiveness that prevents the thermoplastic resin composition from peeling off can be maintained. The thickness of the copper foil is not particularly limited, but is preferably 3 to 35 μm. On the other hand, known release films can be used, and specific examples include polyethylene terephthalate and polybutylene terephthalate. When these have poor adhesion to the thermoplastic resin composition, it is also possible to attach fine irregularities to the surface of the release film. This is selected and used without shrinkage or melting in a process such as lamination molding.

  The method for forming the first resin composition layer on one side of the copper foil or release film is not particularly limited, and the first resin composition solution dissolved in the solvent is applied to the copper foil or release film with a roll or the like and dried. A known method is used, such as a method, a method in which the first resin composition is heated and melted without a solvent and extruded into a sheet shape, and then bonded to a copper foil or a release film by heating or the like by lamination. The thickness of the first resin composition is not particularly limited, and is preferably 1 to 10 μm. The surface of the first resin composition layer formed on the copper foil or the release film is to smooth the surface of the second resin composition layer when the first resin composition layer is dissolved and removed after the lamination molding, Preferably, the surface unevenness is 3 μm or less.

  If the thermosetting resin composition used for the second resin composition layer of the B-stage resin composition sheet with a copper foil or a release film is a known thermosetting resin composition used for a printed wiring board, There is no particular limitation. Examples of these resins include epoxy resins, polyimide resins, cyanate ester resins, maleimide resins, double bond-added polyphenylene ether resins, and resin compositions such as bromine and phosphorus-containing compounds of these resins. Species or two or more are used in combination. From the viewpoint of reliability such as migration resistance and heat resistance, it is preferable to use a resin composition containing a cyanate ester resin as an essential component, for example, an epoxy resin. For these thermosetting resins, known catalysts, curing agents, and curing accelerators are used as necessary.

  The cyanate ester resin suitably used for the second resin composition layer is a compound having two or more cyanato groups in the molecule. Specific examples include 1,3- or 1,4-dicyanatobenzene, 1,3,5-tricyanatobenzene, 1,3-, 1,4-, 1,6-, 1,8-, 2 , 6- or 2,7-dicyanatonaphthalene, 1,3,6-tricyanatonaphthalene, 4,4-dicyanatobiphenyl, bis (4-dicyanatophenyl) methane, 2,2-bis (4-cyanato Phenyl) propane, 2,2-bis (3,5-dibromo-4-cyanatophenyl) propane, bis (4-cyanatophenyl) ether, bis (4-cyanatophenyl) thioether, bis (4-cyanatophenyl) ) Sulfone, tris (4-cyanatophenyl) phosphite, tris (4-cyanatophenyl) phosphate, and cyanates obtained by the reaction of novolac and cyanogen halide.

  In addition to these, phenol novolac type cyanic acid described in JP-B-41-1928, 43-18468, 44-4791, 45-11712, 46-41112, 47-26853 and JP-A-51-63149, etc. Ester compounds and the like can also be used. Naphthalene-type cyanate ester compounds can also be used. Further, a prepolymer having a molecular weight of 400 to 6,000 having a triazine ring formed by trimerization of cyanate groups of these cyanate ester compounds is used. This prepolymer is obtained by polymerizing the above-mentioned cyanate ester monomers using, for example, acids such as mineral acids and Lewis acids; bases such as sodium alcoholates and tertiary amines; salts such as sodium carbonate and the like as catalysts. It is done. This resin also contains a partially unreacted monomer and is in the form of a mixture of a monomer and a prepolymer, and such a raw material is suitably used for the application of the present invention. Furthermore, cyanated polyphenylene ether resin can also be used. A monofunctional cyanate ester compound can also be added to these in an amount that does not significantly affect the properties. 1 to 10% by weight is preferred. These cyanate ester compounds are not limited to those described above, and known compounds can be used. These may be used alone or in combination of two or more.

  As an epoxy resin suitably used in combination with a cyanate ester resin, known resins can be used. Specifically, bisphenol A type epoxy resin, bisphenol F type epoxy resin, phenol novolac type epoxy resin, cresol novolac type epoxy resin, alicyclic epoxy resin, biphenyl type epoxy resin, fluorene type epoxy resin, resorcin type epoxy resin, Naphthalene type epoxy resins, phenol aralkyl type epoxy resins, biphenyl aralkyl type epoxy resins, epoxidized polyphenylene ether resins; polyepoxy compounds epoxidized with double bonds such as butadiene, pentadiene, vinylcyclohexene, dicyclopentyl ether; polyols, And polyglycidyl compounds obtained by the reaction of hydroxyl group-containing silicon resins with epohalohydrin. Moreover, these well-known bromine addition resin, phosphorus containing epoxy resin, etc. are mentioned. These may be used alone or in combination of two or more.

  In the resin composition used for the second resin composition layer, various additives can be blended as desired within a range that does not impair the original characteristics of the composition. These additives include unsaturated double bond-containing monomers such as unsaturated polyesters and prepolymers thereof; polybutadiene, maleated butadiene, butadiene-acrylonitrile copolymer, polychloroprene, butadiene-styrene copolymer, poly Low molecular weight liquid to high molecular weight elastic rubber such as isoprene, butyl rubber, fluoro rubber, natural rubber; polyethylene, polypropylene, polybutene, poly-4-methylpentene, polystyrene, AS resin, ABS resin, MBS resin, styrene-isoprene Rubber, acrylic rubber, these core-shell rubbers, polyethylene-propylene copolymers, 4-fluoroethylene-6-fluoroethylene copolymers; high molecular weight prepolymers such as polycarbonate, polyphenylene ether, polysulfone, polyester, polyphenylene sulfide Properly oligomer; are exemplified polyurethane, etc., it is suitably used. In addition, other known organic and inorganic fillers, dyes, pigments, thickeners, lubricants, antifoaming agents, dispersants, leveling agents, photosensitizers, flame retardants, brighteners, polymerization inhibitors, thixotropic properties Various additives such as an imparting agent are used in appropriate combination as desired. If necessary, the compound having a reactive group is appropriately mixed with a curing agent and a catalyst. In particular, when drilling with a carbon dioxide laser, an inorganic filler is suitably added to improve the hole shape. For example, generally known materials such as silica, spherical silica, alumina, talc, calcined talc, wollastonite, synthetic mica, titanium oxide, and aluminum hydroxide are used. Furthermore, those having a known shape such as these needle-like ones can also be used.

  In order to improve the rigidity of the entire printed wiring board, it is preferable to use a base material for the second resin composition layer used for the copper foil or the B-stage resin composition sheet with a release film. As a base material to be used, if it is a well-known base material used for a printed wiring board, it will not specifically limit. Specifically, generally known non-woven fabrics and woven fabrics of glass fibers such as E, NE, D, S, and T glass; generally known non-woven fabrics and woven fabrics of organic fibers such as polyoxazole, wholly aromatic polyamide, and liquid crystalline polyester These mixed papers; polyimide films, wholly aromatic polyamide films, polyoxazole films, liquid crystal polyester films, and the like. These base materials are preferably subjected to a known surface treatment or the like in order to improve adhesion with the resin.

  The method for forming the second resin composition layer on the first resin composition layer of the copper foil or the B-stage resin composition sheet with a release film is not particularly limited. When using a material, the second resin composition varnish is applied to a substrate and dried to form a B-stage, or the second resin composition sheet formed by the method for forming the first resin composition layer, etc., A known method is used, such as a method of arranging on both surfaces of the substrate and integrating them by thermocompression bonding or the like to produce a prepreg and then press-bonding it onto the first resin composition layer by lamination or the like. The thickness of the second resin composition layer is not particularly limited, but is preferably 4 to 100 μm, and is appropriately selected depending on the application. For example, when used for a printed circuit board for flip chip mounting, the thickness is preferably 10 to 80 μm, and the conductive circuit of the substrate on which the conductive circuit is formed by the thickness of the conductive circuit of the laminated substrate, the copper residual ratio, etc. The thickness of the upper thermosetting resin composition (a) layer to be coated, preferably 1 to 70 μm on the conductor circuit. The degree of cure of the second resin composition is B stage when it is formed on the first resin composition layer. As described above, the B-stage resin composition sheet with the copper foil or release film of the present invention is obtained, and can be used as a B-stage resin composition sheet for general build-up lamination.

  Next, the manufacturing method of the printed wiring board for flip chip mounting which uses the B stage resin composition sheet | seat with a copper foil or a release film of this invention is based on the following manufacturing process. (1) The second resin composition layer surface of the B-stage resin composition sheet is disposed to face at least the semiconductor chip mounting surface of the substrate on which the conductor circuit is formed, and is heated and cured to obtain a semiconductor chip mounting substrate. (2) After forming blind via holes and / or through holes in the semiconductor chip mounting portion of the semiconductor chip mounting substrate, desmearing is performed if necessary, and then copper plating is performed to fill the hole with copper plating. (3) After the surface layer copper foil and / or the copper plating part is etched in the thickness direction up to the first resin composition layer surface, (4) the first resin composition layer is not dissolved in the copper plating. A method for producing a printed circuit board for mounting on a flip chip, characterized in that it is dissolved and removed to the surface of the second resin composition layer with a chemical solution, and the tip portion of the copper plating filling portion protrudes from the surface of the second resin composition layer. Details, (2) after the process, to smooth the surface by polishing the copper plated surface. Thereby, the surface of the copper plating filling part hole becomes the same height and smooth, and the defect at the time of bump formation is further improved. After the step (4), (5) the exposed tip part of the copper plating filling part is removed. This is a manufacturing method in which a bump metal is attached to the tip of a copper plating filling portion coated with a protective metal such as nickel plating, gold plating, or solder plating, and a printed wiring board is manufactured by the above process. Thus, a flip-chip mounting printed wiring board in which semiconductor chip mounting bumps are formed on the printed wiring board is obtained.

  The board | substrate which forms the conductor circuit used by this invention is not specifically limited, The well-known metal foil tension board for printed wiring board materials, Preferably a copper tension board can be used. Specifically, inorganic fiber and / or organic fiber-based copper-clad laminates, heat-resistant film-based copper-clad plates using thermosetting resin compositions and / or thermoplastic resin compositions, and further these Known materials such as composite base material copper clad laminates obtained by combining these base materials, multilayer copper clad plates, multilayer copper clad plates prepared by the additive method, and the like can be used. The conductor thickness of the substrate in which the conductor circuit is formed on the metal foil-clad plate is not particularly limited, but is preferably 3 to 35 μm. On this conductor circuit, a known treatment for improving the adhesion of the copper foil or the B-stage resin composition sheet with a release film to the resin, for example, black copper oxide treatment, chemical treatment (for example, CZ treatment by Meck Co.) is performed. Is preferred.

The step (1) of the method for producing a printed circuit board for flip chip mounting includes the second resin of the B stage resin composition sheet with copper foil or release film on at least the semiconductor chip mounting surface of the substrate on which the conductor circuit is formed. It arrange | positions so that a composition layer surface may be opposed, it heats and hardens | cures, and it is set as the substrate for semiconductor chip mounting. Lamination conditions are not particularly limited. Preferably, lamination molding is performed at a temperature of 100 to 250 ° C., a pressure of 5 to 40 kgf / cm ² , and a degree of vacuum of 30 mmHg or less for 30 minutes to 5 hours. Lamination may be performed under these conditions from the beginning to the end, but it is also possible to laminate and form until gelation, and then take out and post-cure in a heating furnace. Of course, after semi-curing, the surface copper plating portion and the metal foil are removed by etching to the position of the first resin composition layer surface, and further to the surface of the second resin composition with a chemical solution that dissolves the first resin composition layer. It is also possible to melt and cause the tip of the copper plating filling portion to protrude and to be post-cured. This can be appropriately selected depending on the resistance of the resin to the chemical solution. The semiconductor chip mounting protrusion can be formed on the back surface in the same manner when the semiconductor chip is mounted on the back surface. Even if the B stage resin composition sheet on the side to which the solder ball on the back surface of the flip chip mounting surface is bonded is laminated using the copper foil or the B stage resin composition sheet with a release film, the second resin composition A copper foil attached only to the resin layer or a B-stage resin composition sheet with a release film may be used. However, from the viewpoint of reliability and the like, preferably the copper foil attached only to the second resin composition resin layer or A B-stage resin composition sheet with a release film is used.

  In the step (2) of the method of manufacturing the printed circuit board for flip chip mounting, blind via holes and / or through holes are formed in the semiconductor chip mounting substrate by a known method. The method for forming the holes in the substrate is not particularly limited, and known methods can be used. For example, a known UV laser such as a UV-YAG laser or a UV-Vanadate laser is used if the pore diameter is 20 to 100 μm, and a carbon dioxide gas laser is used if the pore diameter is 60 to 150 μm. The blind via hole can be processed by a known method such as plasma. The through hole can also be formed by a metal drill. When a UV-YAG laser or UV-Vanadate laser is used, blind via holes and / or through holes can be formed by direct laser irradiation. When drilling with a carbon dioxide laser, a method for forming a blind via hole by forming a hole of a predetermined size in a copper foil in advance and processing the resin in this hole (conformal mask method), copper The foil is treated with a chemical solution to make irregularities, and a carbon dioxide laser is directly irradiated on the foil to blind via holes and through holes, and the copper foil surface is treated with black copper oxide before blind via holes and through holes. Blind via holes are formed by a generally known method such as a method of drilling, a method of arranging a drilling auxiliary material on the surface of the copper foil, and a method of drilling blind via holes or through holes. When a release film is used, holes can be formed with a carbon dioxide laser or UV laser. It is preferable that the release film is peeled off after the processing because the resin and substrate processing scraps are scattered and adhere on the release film.

  Thereafter, the holed semiconductor chip mounting substrate is plated with copper, the entire substrate is plated with copper, and the inside of the hole is filled with copper. Copper plating is performed by a known method of filling blind via holes by electroless copper plating or electrolytic copper plating. The surface of the copper plating is preferably polished and smoothed after the copper plating is completed. When blind via holes and / or through-holes are formed with a carbon dioxide laser, a resin layer slightly remains on the copper foil in the hole, so that a resin residue is removed by performing a treatment such as a desmear process. In this case, copper foil burrs are generated in the holes, which may be removed by etching or used as they are. Thereafter, the whole is plated with copper, and the blind via hole and / or the through hole is filled with copper plating.

  In the step (3) of the method of manufacturing the printed circuit board for flip-chip mounting, the surface copper plating portion and the copper foil are etched in a plane in the thickness direction up to the position of the first resin composition layer surface. The etching method is based on a known copper plating part used in the manufacturing process of the printed wiring board and a copper foil etching method.

  In the step (4) of the method of manufacturing the printed circuit board for flip chip mounting, the first resin composition layer is dissolved by using a chemical solution in which the copper plating is difficult to dissolve, and the surface of the second resin composition layer is exposed. . As the chemical solution to be used, an organic solvent or the like in which the thermoplastic resin is dissolved is used. Specifically, although depending on the type of the second resin composition, generally one or two or more ketones such as methyl ethyl ketone; polar solvents such as dimethylformamide; aromatic hydrocarbons such as toluene and xylene; Is used as appropriate depending on the chemical resistance of the first resin composition and the second resin composition. The first resin composition layer is a resin composition that is easy to dissolve in the chemical solution, and the copper plating portion hardly dissolves in the chemical solution, so that the tip portion of the copper plating filling portion is 1 to 10 μm from the second resin composition layer surface. A printed wiring board having a protruding shape and a smooth second resin composition surface is obtained. Through these series of steps, a flip chip mounting printed wiring board having a structure in which a bump for connecting a semiconductor chip is formed on the printed wiring board side is manufactured.

  Next, the circuit exposed on the front and back surfaces of the printed wiring board is covered with a protective metal such as nickel plating, gold plating, or solder plating. Of course, without covering with a protective metal, immediately attach a known bump metal such as solder, solder paste, etc. on the tip of the copper plating filling part, and if necessary, heat the semiconductor on the top of the copper plating filling part. It is possible to bond the bump metal for chip connection, but it takes time to bond the solder ball on the back surface, and the circuit surface is oxidized and rust is generated. To do. Thereafter, a bump metal is bonded onto the convex top of the copper-plated filling portion, and the bump metal surface and the bump connection surface of the semiconductor chip are mounted and connected, and the flip chip mounted printed wiring board and To do. The gap between the semiconductor chip and the surface layer of the printed wiring board is preferably filled with an underfill resin. Since the second resin composition layer surface on the surface of the printed wiring board is smooth, the underfill resin is surely filled. Further, since a UV selective thermosetting resist is not used to coat the conductor circuit, a flip-chip mounted printed wiring board having excellent heat resistance and reliability can be obtained.

The present invention will be specifically described below with reference to examples and comparative examples. “Parts” represents parts by weight.
Synthesis example 1
After adding 2100 g of N-methyl-2-pyrrolidone (hereinafter referred to as NMP) to 108 g (1 mol) of p-phenylenediamine in a 5 liter flask and dissolving with stirring. 294 g (1 mol) of 3,3 ′, 4,4′-biphenyltetracarboxylic dianhydride was gradually added while cooling to 30 ° C. or lower, and then reacted for 2 hours to obtain an NMP solution A of polyamic acid.

Example 1
400 parts of 2,2-bis (4-cyanatophenyl) propane monomer was melted at 150 ° C. and reacted for 4 hours with stirring to obtain a mixture of monomer and prepolymer, which was dissolved in methyl ethyl ketone, and varnish B and did. Bisphenol A type epoxy resin (Epicoat 828, manufactured by Japan Epoxy Resin Co., Ltd.) 350 parts, biphenyl type epoxy resin (NC3000, manufactured by Nippon Kayaku Co., Ltd.) 50 parts, phenol novolac type epoxy resin (DEN431, Dow (Chemical Co., Ltd.) 100 parts, 100 parts of acetylacetone iron, 5 parts of green pigment are dissolved and mixed in methyl ethyl ketone, and 500 parts of baked talc (BST200, Nihon Talc Co., Ltd.) is added and mixed evenly. Varnish C. Also, a solution in which polycarbonate is dissolved in a mixed solvent of methyl ethyl ketone and N, N'-dimethylformamide is applied to one side of a 25 μm thick PET film (surface irregularity Max.2.2 μm), dried, and a 9 μm thick thermoplastic resin The 1st resin composition sheet | seat D with a release film which formed the composition layer was produced. Next, the above-mentioned varnish C was impregnated into a 30 μm-thick liquid crystal polyester nonwoven fabric substrate, dried, and a B-stage thermosetting resin composition sheet having a gelation time of 40 μm (at 170 ° C., hereinafter the same) 112 seconds was obtained. Then, a release PET film having a thickness of 25 μm was laminated on both sides by bonding at 90 ° C. with a linear pressure of 4 kgf / cm to obtain a second resin composition sheet E. The PET film on one side of this sheet E is peeled off, this surface is placed facing the resin surface of the first resin composition sheet D with a release film, and laminated and bonded at 90 ° C. with a linear pressure of 5 kgf / cm. A B-stage resin composition sheet F with a release film having the first and second resin composition layers formed thereon was produced. On the other hand, after etching the surface copper foil (12μm) of BT resin copper clad laminate (CCL-HL832, Mitsubishi Gas Chemical Co., Ltd.) with a thickness of 0.2mm to 3μm, a through hole with a hole diameter of 75μm was formed with a metal drill. It formed in the whole, the copper plating was made to adhere to the whole after a desmear process, and the inside of a through-hole was filled with copper plating. After polishing and smoothing the front and back of the copper clad laminate, a circuit was formed, and the surface layer circuit was subjected to black copper oxide treatment to obtain a circuit board G. A B-stage resin composition sheet F with a release film is placed on the semiconductor chip mounting surface side of the circuit board G, and a PET film on one side of the second resin composition sheet E is attached to the surface to which the solder balls on the back surface are connected. The substrate H for semiconductor chip mounting was manufactured by laminating and arranging for 3 hours under vacuum of 180 ° C., 20 kgf / cm ² , and 10 mmHg. The substrate H was irradiated with a carbon dioxide laser one side at a time, and only a blind via hole for forming a semiconductor chip bump having a hole diameter of 80 μm was formed on the surface of the semiconductor chip mounting portion. On the opposite back side, a blind via hole having a hole diameter of 150 μm was similarly formed. After the PET film was peeled, the resin residue remaining in the blind via hole was removed with a desmear solution, and then the inside of the blind via hole was filled with copper plating and the entire substrate was plated with copper. Thereafter, the copper plating portion of the surface layer is etched in the thickness direction to expose the first resin composition layer on the front surface and the second resin composition layer on the back surface, and then a mixed solvent of methyl ethyl ketone and N, N′-dimethylformamide The first resin composition layer on the surface was dissolved and removed to protrude the tip of the copper plating filling portion on the surface, and then nickel plating and gold plating were applied to produce a printed wiring board for flip chip mounting. Thereafter, bump solder was attached to the noble metal-plated tip portion of the copper plating filling portion, and a semiconductor chip on which a circuit for connecting bumps was formed on the back surface was placed thereon, and the semiconductor chip was mounted and bonded by heating. Next, an underfill resin was filled between the semiconductor chip and the surface thermosetting resin composition layer and cured, and solder balls were bonded to the back surface to obtain a flip-chip mounted printed wiring board. The evaluation results are shown in Table 1.

Example 2
Mixing 450 parts of 2,2-bis (4-cyanatophenyl) propane monomer and 50 parts of bis (4-maleimidophenyl) methane monomer at 150 ° C and reacting for 5 hours with stirring to mix monomer and prepolymer Then, it was dissolved and mixed in methyl ethyl ketone and N, N′-dimethylformamide to obtain Varnish I. 300 parts of bisphenol A type epoxy resin (Epicoat 828), 100 parts of phenol novolac type epoxy resin (DEN431), 100 parts of naphthalene type epoxy resin (ESN-175S, manufactured by Nippon Steel Chemical Co., Ltd.), zinc octylate 0.3 Parts and 5 parts of a green pigment were dissolved and mixed in methyl ethyl ketone to obtain varnish J. Also, a solution of polyphenylene ether resin dissolved in toluene was applied to one side of a rolled copper foil (surface irregularity Max.0.9 μm) with a thickness of 20 μm and dried, and a thermoplastic resin composition with a thickness of 7 μm was dried. The 1st resin composition sheet K with copper foil which formed the physical layer was produced. Next, the varnish J was impregnated into a glass fabric of 30 μm thickness and dried to prepare a resin composition sheet having a gelation time of 123 seconds with a thickness of 40 μm. Covering and laminating and bonding at a linear pressure of 70 ° C. and 5 kgf, a second resin composition sheet L was obtained. The PET film on one side of this sheet L is peeled off, placed on the resin surface of the first resin composition sheet K with copper foil, and laminated and bonded at 90 ° C. and a linear pressure of 5 kgf. A B-stage resin composition sheet M with a copper foil on which a physical layer was formed was produced. On the other hand, a BT resin copper clad laminate (CCL-HL830, manufactured by Mitsubishi Gas Chemical Co., Ltd.) with a thickness of 0.2mm and double-sided 3μm copper foil was drilled with a metal drill on the outside of the semiconductor chip mounting part. After the desmear treatment, the whole is plated with copper and the inside of the through hole is filled with copper plating, the surface is polished and smoothed, a circuit is formed, and the surface layer circuit is subjected to CZ treatment of MEC to obtain a circuit board N . The B-stage resin composition sheet M with the copper foil is placed on the semiconductor chip mounting surface side of the circuit board N, and the back surface is arranged by separating the release films on both sides of the B-stage resin composition sheet L, and the outside A 20 μm-thick rolled copper foil whose surface was nickel-treated was placed on the substrate, and was laminated and formed at a temperature of 190 ° C., 20 kgf / cm ² , and a vacuum of 10 mmHg or less for 2 hours to obtain a substrate O for mounting a semiconductor chip. A laser drilling entry sheet (LSE30, manufactured by Mitsubishi Gas Chemical Co., Ltd.) is placed on the surface of the substrate O, and a laser drilling backup sheet (LSB90, manufactured by Mitsubishi Gas Chemical Co., Ltd.) is placed on the back surface. After laminating and bonding with a pressure of 7 kgf / cm at ℃, UV-Vanadate laser is irradiated on the surface of the semiconductor chip mounting part to open blind via holes and through holes with a hole diameter of 40 μm, and after peeling the front and back drilling auxiliary sheets Then, the copper foil on the back surface was irradiated with UV-Vanadate laser, and solder ball connection holes were similarly formed with a blind via hole diameter of 150 μm. After desmearing, the entire board is plated with copper, and the blind via hole and through hole are filled with copper plating. After the surface copper plating is polished and smoothed, the copper plating on the surface layer and the copper foil are etched. The first resin composition layer on the front surface and the second resin composition layer on the back surface are exposed, the first resin composition layer on the front surface is dissolved and removed with toluene, and the tip portion of the copper plating filling portion on the surface is removed. And a nickel-plated or gold-plated printed wiring board for flip chip mounting. Thereafter, in the same manner as in Example 1, a semiconductor chip was mounted and bonded, filled with an underfill resin, cured, and solder balls were joined to form a flip chip mounted printed wiring board. The evaluation results are shown in Table 1.

Example 3
Brominated bisphenol A type epoxy resin (Epicoat 5045, manufactured by Japan Epoxy Resins Co., Ltd.) 800 parts, phenol novolac type epoxy resin (DEN431) 200 parts, green pigment 5 parts, dicyandiamide 35 parts, 2-ethyl-4-methylimidazole One part was dissolved and mixed in a mixed solvent of methyl ethyl ketone and dimethylformamide to obtain varnish P. This varnish P was applied to one side of a PET film having a thickness of 25 μm and dried to prepare a B-stage resin composition sheet Q with a release film having a thickness of 25 μm and a gel time of 154 seconds. In addition, after heating the polyamic acid NMP solution A of Synthesis Example 1 to 60 ° C. to lower the viscosity, this was applied onto the matte surface (surface roughness Rz: 3.5 μm) of 12 μm thick electrolytic copper foil. Then, the reaction was carried out in a nitrogen stream at 140 ° C. for 30 minutes, 200 ° C. for 30 minutes, and further at 270 ° C. for 1 hour to obtain a first resin composition sheet R with a copper foil having a resin layer thickness of 4 μm. Next, the resin surface of the B-stage resin composition sheet Q with a release film is placed opposite to the resin surface of the first resin composition sheet R with copper foil, and the linear pressure at 90 ° C. and 5 kgf / cm. The B-stage resin composition sheet S with copper foil on which the first and second resin composition layers were formed was prepared by laminating and bonding. Further, the B-stage resin composition sheet Q with the release foil film is placed on the matte surface of the electrolytic copper foil having a thickness of 12 μm so that the resin surface of the B-stage resin composition sheet Q with the release film is laminated and bonded in the same manner. Produced. The B-stage resin composition sheet S with copper foil is placed on the surface of the circuit board U processed in the same manner as in Example 2, except that the thickness of the copper-clad laminate is 0.8 mm, and the back surface is provided with copper foil B. Place the stage resin composition sheet T, remove it from the press machine after lamination molding for 30 minutes under a vacuum of 160 ° C, 20kgf / cm ² , 10mmHg, and cure it at 170 ° C for 5 hours in a heating furnace. Got. Using this substrate V, drilling was performed in the same manner as in Example 2, and the entire surface was plated with copper and the inside of the hole was filled with copper plating. Then, the surface layer was polished and smoothed, and etched to obtain copper plating and copper foil. And the second resin composition layer on the back surface was exposed, the first resin composition layer on the surface layer was dissolved and removed with an aqueous sodium hydroxide solution, and the flip chip mounting print was performed in the same manner as in Example 2. A wiring board was prepared, a semiconductor chip was mounted and connected, filled with an underfill resin and cured, and solder balls were joined to form a flip chip mounted printed wiring board. The evaluation results are shown in Table 1.

Comparative Example 1
In Example 1, instead of the B-stage resin composition sheet F with the release film and the second resin composition sheet E, a UV selective thermosetting resist was used, applied to the surface of the circuit board, exposed, developed, Nickel plating and gold plating were applied to obtain a printed wiring board. A semiconductor chip was mounted on this printed wiring board, adhered in the same manner, filled with underfill resin, cured, and solder balls were bonded to form a flip chip mounted printed wiring board. The evaluation results are shown in Table 1.

Comparative Example 2
In Example 2, instead of the B-stage resin composition sheet M with copper foil and the second resin composition sheet L, a pattern plating resist is used and applied to a thickness of 14 μm on the circuit board from above the circuit. Then, a hole having a hole diameter of 40 μm was developed and opened on the circuit, and the hole was filled with copper plating so as to be the same height as the plating resist, thereby producing a printed wiring board for flip chip mounting. Thereafter, solder was bonded onto the protrusions, and in the same manner as in Example 2, a semiconductor chip was mounted and connected, then an underfill resin was poured and cured, solder balls were bonded, and a flip chip mounted printed wiring board was obtained. Evaluation results are shown in Table 1.

Table 1
Example Comparison example
Item 1 2 3 1 2
Semiconductor bump connectivity
(n / 500) 0/0/0/0/55 /
Underfill resin filling degree
(m / 100) 0/0/0/22/6 /
Surface roughness of thermosetting resin layer <3 <3 <3 14 10
(Μm)
Moisture without heat resistance No change No problem swelling occurred swelling occurred migration resistance ordinary state ^{6x10 14 7X10 14 6X10 14 6x10 14} 5X10 14
200hrs. 2x10 ¹¹ 4x10 ¹¹ 2x10 ¹⁰ 3x10 ⁹ 8x10 ⁹
500hrs. 3x10 ¹⁰ 5x10 ¹⁰ <10 ⁸ <10 ⁸ <10 ⁸
700hrs. 2x10 ¹⁰ 5x10 ¹⁰ − − −
1000hrs. 2x10 ¹⁰ 4x10 ¹⁰ − − −
Elastic modulus (kgf / mm ² ) 2345 2413 2157 − 1950

<Measurement method>
1) Semiconductor bump connection degree: The presence or absence of connection failure of the semiconductor chip was electrically confirmed. (Indicates the number of tests in the denominator and the number of poor connections in the numerator)
2) Resin filling degree: The filling state between the semiconductor chip and the substrate of the underfill resin was confirmed with an ultrasonic probe. (Indicates the number of inspections in the denominator and the number of poor packing in the numerator)
3) Surface unevenness: The surface unevenness of the surface of the printed wiring board on which the semiconductor chip was mounted was measured with a roughness meter to show the maximum unevenness.
4) Moisture absorption and heat resistance: Using printed wiring boards without solder balls, JEDEC Level II was used to observe the presence or absence of abnormal appearance at a lead reflow soldering temperature of Max.
5) Migration resistance: Using a printed wiring board with no semiconductor chip mounted with a distance between bump pad conductors on the surface layer of 50 μm, the insulation resistance value between circuits was measured by applying 85 ° C and 85% RH, 100VDC.
6) Modulus of elasticity: Without forming circuit conductors and holes, make a laminate with only the same structure and measure the modulus of elasticity according to the JIS C6481 DMA method. Indicated.

It is a manufacturing process figure of the flip-chip mounting printed wiring board of Example 2. FIG. (1) Diagram of B-stage resin composition sheet with copper foil with two resin composition layers attached on the circuit board (upper side only) (2) Blind vias and through holes drilled by laser (f) Image (3) Formed blind via hole (g) and through hole (h) (4) Image of etching surface polished copper plating (i) with etchant (j) It is a manufacturing process figure of the flip-chip mounting printed wiring board of Example 2. FIG. (5) Image of dissolving the first resin composition layer (l) with the chemical solution (m) (6) Figure (7) where the first resin composition layer is dissolved and the tip part (n) of the copper plating filling part protrudes Figure with bump metal (o) attached (8) Figure with semiconductor chip (p) connected and mounted It is a manufacturing process of the printed wiring board of the comparative example 2. FIG. (1) A pattern plating resist is applied, dried, exposed, and developed (2) A copper plating is filled up to the height of the pattern plating resist at a place where copper plating is developed and removed (3) A bump metal is attached

Explanation of symbols

a copper foil b first resin composition c second resin composition d conductor circuit e laminated board f laser beam g blind via hole processed by laser
h Blind via hole filled with copper plating i Polished and smooth copper plating surface j Etching solution k Copper plating etched to first resin composition layer l Exposed first resin composition m First resin composition Material layer solution n Protruding tip of copper plating filling area o Bump metal p Semiconductor chip q Pattern plating resist r Holes removed by development s Copper plating depression plated to pattern plating resist surface t Bump connection of semiconductor chip Circuit
u Through holes drilled with laser
v Through hole filled with copper plating

Claims (8)

A first resin composition layer made of a thermoplastic resin composition is formed on one side of a copper foil or a release film, and a second resin composition layer made of a thermosetting resin composition is formed on the resin composition layer. B-stage resin composition sheet with copper foil or release film. The B-stage resin composition sheet according to claim 1, wherein the thickness of the first resin composition layer is 1 to 10 µm. The B-stage resin composition sheet according to claim 1 or 2, wherein the second resin composition layer is reinforced with a base material. The B-stage resin composition sheet according to any one of claims 1 to 3, wherein the second resin composition is a resin composition containing a cyanate ester resin as an essential component. (1) The second resin composition layer surface of the B-stage resin composition sheet according to any one of claims 1 to 4 is disposed to face at least a semiconductor chip mounting surface of a substrate on which a conductor circuit is formed, and heated. And hardened to make a substrate for mounting semiconductor chips,
(2) After forming blind via holes and / or through holes in the semiconductor chip mounting portion of the semiconductor chip mounting substrate, copper plating is performed to fill the hole interior with copper plating,
(3) After etching the surface copper foil and / or the copper plating portion in the thickness direction up to the first resin composition layer surface,
(4) The first resin composition layer is dissolved and removed up to the second resin composition layer surface with a chemical solution that does not dissolve the copper plating, and the tip portion of the copper plating filling portion protrudes from the second resin composition layer surface. A manufacturing method of a printed wiring board for flip chip mounting. 6. The method for manufacturing a printed circuit board for flip chip mounting according to claim 5, wherein after the step (2), the surface of the copper plating is polished to smooth the surface. 7. The method for manufacturing a printed circuit board for flip chip mounting according to claim 5 or 6, wherein after the step (4), (5) the exposed tip portion of the copper plating filling portion is covered with a protective metal. The method for producing a printed circuit board for flip chip mounting according to any one of claims 5 to 7, wherein a bump metal is attached to a tip portion of a copper plating filling portion coated with a protective metal. .

Images