JP2000077567A - Manufacture of printed wiring board - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent a metal core from absorbing moisture from its rear surface, and to prevent popcorn phenomenon and to improve heat-dissipation characteristics by forming via holes on both surfaces of a metal core, and filling the inside of the via hole with a metal plating. SOLUTION: Through-holes (e) of 0.25 mm diameter are so opened at the center of a through-hole part so as not to make contact with a metal core, and via holes (d) of 120 μm diameter are opened so as to reach the metal core with a carbon dioxide laser from front/rear surfaces, and then plated with copper. For the via parts on front/rear surfaces, a copper plating is deposited to fill all holes. Then, circuits are formed on front and rear surfaces, where a part except for a semiconductor chip mounting part, bonding pat part, and ball pad part is coated with a plating resist k, for plating with nickel and gold. On the filled/plated copper foil part, a 13 mm square semiconductor chip g is bonded/fixed with a silver paste i, and the semiconductor chip mounting part, a wire part, and the bonding pat part are sealed with resin, and then a solder ball (j) is jointed to a solder ball pad on the rear surface.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of manufacturing a novel printed wiring board for a semiconductor plastic package containing a metal core. More specifically, the present invention relates to a method for manufacturing a printed wiring board in which via holes are formed on both surfaces of a metal core and the inside of the via holes is filled with metal plating. The printed wiring board obtained by the manufacturing method of the present invention is suitable for use in semiconductor plastic packages having a relatively high wattage and a high density of terminals such as microprocessors, microcontrollers, ASICs, and graphics.

[0002]

2. Description of the Related Art Conventionally, as a semiconductor plastic package, a semiconductor chip such as a plastic ball grid array (P-BGA) or a plastic land grid array (P-LGA) is fixed on the upper surface of a plastic printed wiring board. Bonded to the conductor circuit formed on the upper surface of the printed wiring board by wire bonding, and formed solder pads on the lower surface of the printed wiring board to connect to the motherboard printed wiring board, and plated the front and back circuit conductors 2. Description of the Related Art A semiconductor plastic package having a structure in which a semiconductor chip is sealed with a resin by connecting through a formed through hole is known. In the known structure, in order to diffuse heat generated from the semiconductor to the motherboard printed wiring board, a plated heat diffusion through hole is formed from the upper metal foil for fixing the semiconductor chip to the lower surface. Through the through holes, moisture is absorbed by the resin adhesive containing silver powder used for fixing the semiconductor, and there is a danger of causing interlayer blisters due to heating during mounting on the motherboard and heating when removing the semiconductor components from the motherboard. This is called the popcorn phenomenon. When this popcorn phenomenon occurs, the package often becomes unusable, and it is necessary to greatly improve this phenomenon. In addition, higher functionality and higher density of semiconductors mean more and more heat generation, and heat dissipation is insufficient with only through holes directly below the semiconductor chip for heat dissipation.

[0003]

SUMMARY OF THE INVENTION An object of the present invention is to provide a printed wiring board for a semiconductor plastic package in which the above problems are improved.

[0004]

According to the present invention, a metal plate having substantially the same size as the printed wiring board is arranged at substantially the center in the thickness direction of the printed wiring board, and the metal plate and the circuit conductors on the front and back sides are arranged. Insulating with a thermosetting resin composition composition, at least a method of manufacturing a metal core-containing printed wiring board having a structure in which circuit conductors on the front and back surfaces are connected by through-hole conductors insulated with the thermosetting resin composition, In the metal plate, in advance, at least a clearance hole for forming a resin-insulated through-hole conductor, or a slit hole is formed,
If necessary, treat the metal surface, and then place a prepreg made of a thermosetting resin composition, a resin sheet, a coating film, or a metal foil with a resin on the upper and lower sides of the metal plate. A metal foil is placed on the outside and laminated under heat and pressure to form a metal-foil-clad laminate with an integrated metal core, and a prepreg, resin sheet, coating film, and thermosetting resin with metal foil with resin By the composition, the hole formed in the metal plate is embedded, and further a hole for a through hole is formed,
After opening the heat dissipation via holes on the front and back, metal plating is performed, the through holes are made conductive, the via holes on the front and back are metal-plated and filled with metal, and a circuit is formed on the metal foil on the front and back,
Form a solder resist layer on the selected part on the front and back,
By applying a noble metal plating to the exposed metal surface to create a printed wiring board, it is possible to obtain a printed wiring board for semiconductor plastic packages with excellent heat dissipation, excellent popcorn phenomenon, and a novel structure. They have found and completed the present invention.

[0005]

BEST MODE FOR CARRYING OUT THE INVENTION A metal plate having substantially the same size as a printed wiring board is disposed substantially at the center of a printed wiring board for a semiconductor plastic package in the thickness direction. In a method for manufacturing a printed wiring board with a metal core having a structure in which the printed wiring boards are connected by through-hole conductors insulated by a curable resin composition, a clearance hole or a slit is formed at least at a position where at least a through-hole is to be formed. A hole is formed, and then a prepreg, a resin sheet, a coating film or a resin-coated metal foil is placed above and below the metal plate, and a metal foil is placed outside the resin layer where the metal foil is not attached, and heated and heated. A metal foil-clad laminate with a metal core was formed by lamination molding under pressure, and the holes formed in the metal plate were filled with the thermosetting resin composition. Drill holes for heat dissipation, and make via holes for heat radiation to reach the metal core on the front and back surfaces.If necessary, treat the surface of the metal core and fill the via holes with metal plating. After conducting the front and back, a circuit is formed on the copper foil on the front and back, and at least the semiconductor chip mounting part, the bonding pad part, and the ball pad part are covered with a plating resist, then precious metal plating is applied and the metal core is included The present invention provides a method for manufacturing a printed wiring board. The obtained printed wiring board is bonded to the metal plating filled via hole formed in the upper semiconductor chip mounting portion with a heat conductive adhesive, and the heat generated in the semiconductor chip passes through the via portion to the metal core. It has a structure that conducts heat and diffuses to the motherboard printed wiring board through vias filled with metal plating on the back surface, so it has good heat dissipation and excellent popcorn phenomenon after moisture absorption. I have. Furthermore, by using a polyfunctional cyanate resin composition as a thermosetting resin composition, it has excellent heat resistance, insulation after pressure cooker, migration resistance, etc., and is suitable as a semiconductor plastic package. is there.

In a known method of fixing a semiconductor chip on the upper surface of a metal-core printed wiring board having a through hole, heat from the semiconductor chip is dropped to a heat dissipation through hole immediately below, similarly to a conventional P-BGA package. Heat must be dissipated and the popcorn phenomenon cannot be improved. The present invention first forms a clearance hole or a slit hole in a through-hole through-hole forming portion of a metal plate, performs a metal foil surface treatment if necessary, and then prepregs on both sides thereof.
Place a resin sheet, paint film, or metal foil with resin, place the metal foil outside the resin layer where the metal foil is not attached,
A metal foil-clad laminate with a metal core is formed by laminating and molding under heat and pressure, and a clearance hole or slit hole formed in the metal plate is embedded with a thermosetting resin composition. Drill through holes so that they do not come in contact with the metal core, and radiate via holes for heat radiation on the front and back surfaces until the metal core is reached by a generally known method such as laser, drill, or plasma. After removing the resin layer remaining on the metal core surface by performing treatment or low-pressure ultraviolet treatment, fill the via holes with metal plating, and also conduct the through holes between the front and back, then place the circuit on the front and back. After forming and covering with a plating resist except at least the semiconductor chip mounting portion, the bonding pad portion, and the ball pad portion, nickel and gold plating are performed. It is a method of making a printed wiring board. It is also possible to coat the surface with a thermosetting resist or a UV resist after performing the noble metal plating on the entire surface.

Although the metal plate used in the present invention is not particularly limited, a metal plate having a high elastic modulus, a high thermal conductivity and a thickness of 30 to 300 μm is preferably used. Specifically, pure copper, other alloys such as Fe, Sn, P, Zr, Zn, etc. having a copper content of 95% or more, or a metal plate obtained by plating the surface of an alloy plate having a low coefficient of thermal expansion with copper is preferably used. .

The shape of the metal plate serving as the metal core of the present invention is a flat plate, in which clearance holes or slit holes are formed in advance. A double-sided metal foil-clad laminate having a thermosetting resin layer formed on the front and back of the metal plate is formed. In the area of mounting the semiconductor chip and in the same area of the corresponding back surface, generally a via hole having a hole diameter of 25 to 300 μm, a mechanical drill such as to reach the metal core of the inner layer, a laser, a generally known method such as plasma. Open. If necessary, desmearing, plasma treatment and the like are performed, and then metal plating is applied so as to completely fill the inside of the via hole. In addition, metal plates are generally provided with clearance holes and slit holes for through holes that connect the upper and lower circuits, and through holes are generally made of mechanical drills, lasers, etc. so that they do not contact the inner layer metal core. It is formed by a known method and plated through-hole.

The surface of the metal plate is oxidized by a known method,
A surface treatment for improving adhesion and electrical insulation such as formation of fine irregularities and film is performed as necessary. An insulating portion is formed on the upper and lower surfaces of the surface-treated metal plate with a thermosetting resin composition. The formation of the insulating portion using the thermosetting resin composition is performed using a prepreg, a resin sheet, a resin-coated metal foil, or a coated resin layer in which a semi-cured thermosetting resin composition is impregnated with a base material and dried. This resin must be a prepreg, resin sheet, resin-coated metal foil, and coated resin layer that have sufficient resin amount and resin flow to fill the clearance holes and slit holes. Then, they are laminated and integrated under heating and pressure, preferably under vacuum.

The through hole for the front and back signal circuits is formed substantially at the center of the metal plate clearance hole or slit hole in which the resin is embedded so as not to contact the metal plate. Via holes on the front and back are laser, mechanical drill,
Drill holes to reach the metal core by a generally known method, such as plasma, desmear treatment, plasma treatment, if necessary,
After removing the resin layer adhering to the metal core surface layer by performing low-pressure ultraviolet treatment or the like, through-hole plating is performed, and further, plating of the via hole is performed. The plating of the via hole portion is performed by copper plating so that the entire hole is filled. By doing so, as compared with a simple metal plating of the via hole wall, conduction reliability of the via hole portion is improved, and a heat conduction area is widened, so that excellent heat dissipation can be obtained. A generally known method can be used for plating.

After forming the front and back circuits, a solder resist layer is formed on selected portions of the front and back surfaces.
Precious metal plating is formed on at least the surface of the wire bonding pad to complete the printed wiring board.

A semiconductor chip is fixed on a surface metal foil on a via hole filled with metal plating using a thermally conductive adhesive, and furthermore, the semiconductor chip and a bonding pad of a printed wiring board circuit are bonded by a wire bonding method. After connection, at least the semiconductor chip, the bonding wires and the bonding pads are sealed with a known sealing resin.

[0013] A solder ball is connected to the solder ball connection conductor pad on the opposite side of the semiconductor chip to form a P-BGA, and the solder ball is superimposed on a circuit on a motherboard printed wiring board, and the ball is melted and connected by heat. When making a P-LGA without attaching a solder ball to the package or mounting it on the motherboard printed wiring board, the solder ball connection conductor pad formed on the motherboard printed wiring board surface and the solder ball conductor for the P-LGA The pads are connected by heating and melting the solder balls.

As the resin of the thermosetting resin composition used in the present invention, generally known thermosetting resins are used. Specific examples include an epoxy resin, a polyfunctional cyanate ester resin, a polyfunctional maleimide-cyanate ester resin, a polyfunctional maleimide resin, and an unsaturated group-containing polyphenylene ether resin. Are used in combination. Polyfunctional cyanate ester resin compositions are preferred from the viewpoints of heat resistance, moisture resistance, migration resistance, electrical properties after moisture absorption, and the like.

The polyfunctional cyanate compound which is a preferred thermosetting resin component of the present invention is a compound having two or more cyanato groups in a 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-cyanatophenyl) 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 cyanate obtained by reacting novolak with cyanogen halide And so on.

In addition to these, Japanese Patent Publication Nos. 41-1928 and 43-1846
8, polyfunctional cyanate compounds described in JP-A-44-4791, JP-A-45-11712, JP-A-46-41112, JP-A-47-26853 and JP-A-51-63149 can also be used. Further, a prepolymer having a molecular weight of 400 to 6,000 and having a triazine ring formed by trimerization of a cyanato group of these polyfunctional cyanate compounds is used. This prepolymer is obtained by polymerizing the above-mentioned polyfunctional cyanate ester monomer with a catalyst such as an acid such as a mineral acid or a Lewis acid; a base such as a tertiary amine such as sodium alcoholate; or a salt such as sodium carbonate. It can be obtained by: The prepolymer also contains some unreacted monomers and is in the form of a mixture of the monomer and the prepolymer, and such a raw material is suitably used for the purpose of the present invention. Generally, it is used after being dissolved in a soluble organic solvent.

As the epoxy resin, a generally known epoxy resin can be used. Specifically, liquid or solid bisphenol A type epoxy resin, bisphenol F type epoxy resin, phenol novolak type epoxy resin, cresol novolak type epoxy resin, alicyclic epoxy resin; butadiene, pentadiene, vinylcyclohexene, dicyclopentyl ether, etc. And polyglycidyl compounds obtained by reacting a polyol, a hydroxyl-containing silicone resin with an epohalohydrin, and the like. These may be used alone or in combination of two or more.

As the polyimide resin, generally known ones can be used. Specific examples include a reaction product of a polyfunctional maleimide and a polyamine, and a polyimide having a terminal triple bond described in JP-B-57-005406.

These thermosetting resins may be used alone, but it is preferable to use them in an appropriate combination in consideration of the balance of properties.

Various additives can be added to the thermosetting resin composition of the present invention, if desired, as long as the inherent properties of the composition are not impaired. These additives include polymerizable double bond-containing monomers such as unsaturated polyesters and prepolymers thereof; polybutadiene, epoxidized butadiene, maleated butadiene, butadiene-
Low molecular weight liquid to high molecular weight elastic rubbers such as acrylonitrile copolymer, polychloroprene, butadiene-styrene copolymer, polyisoprene, butyl rubber, fluororubber, natural rubber; polyethylene, polypropylene, polybutene, poly-4-methyl Penten, polystyrene, AS
Resin, ABS resin, MBS resin, styrene-isoprene rubber,
Polyethylene-propylene copolymer, 4-fluoroethylene-
6-fluorinated ethylene copolymers; high molecular weight prepolymers or oligomers such as polycarbonate, polyphenylene ether, polysulfone, polyester, and polyphenylene sulfide; and polyurethane are exemplified and used as appropriate. Other known inorganic or organic fillers, dyes, pigments, thickeners, lubricants, defoamers, dispersants, leveling agents, photosensitizers, flame retardants, brighteners, polymerization inhibitors, thixotropic Various additives such as imparting agents are used in combination as needed. If necessary, the compound having a reactive group is appropriately blended with a curing agent and a catalyst.

The thermosetting resin composition of the present invention itself is cured by heating, but has a low curing rate, and is inferior in workability, economy and the like. Therefore, a known thermosetting catalyst can be used for the thermosetting resin used. Use amount is thermosetting resin 10
0.005 to 10 parts by weight, preferably 0.01 to 5 parts by weight per 0 parts by weight
Parts by weight.

As the reinforcing base material of the prepreg, generally known inorganic or organic woven or nonwoven fabric is used. Specific examples include known glass fiber cloths such as E glass, S glass, and D glass, wholly aromatic polyamide fiber cloths, and liquid crystal polyester fiber cloths. These may be mixed. Alternatively, a thermosetting resin composition applied to the front and back of a film such as a polyimide film and heated to a semi-cured state can be used.

As the outermost metal foil, generally known ones can be used. Preferably, a copper foil, a nickel foil or the like having a thickness of 3 to 18 μm is used.

The diameter of the clearance hole or the width of the slit formed in the metal plate is slightly larger than the diameter of the through hole for front and back conduction. Specifically, the through hole wall and the metal plate clearance hole or slit hole wall are 50 μm
It is preferable that the above distance is insulated by the thermosetting resin composition. For the through hole diameter for front and back conduction,
Although not particularly limited, 50 to 300 μm is preferable.

When preparing the prepreg for a printed wiring board of the present invention, the substrate is impregnated with a thermosetting resin composition and dried to obtain a semi-cured laminated material. Further, a resin sheet in a semi-cured state without using a base material and a metal foil with a resin can also be used. Alternatively, paints can be used. The temperature for forming a resin layer such as a prepreg is generally 100 to 180 ° C. The time is 5 to 60 minutes, and is appropriately selected depending on the desired flow rate.

[0026]

The present invention will be specifically described below with reference to examples and comparative examples. Unless otherwise specified, “parts” indicates parts by weight. Example 1 900 parts of 2,2-bis (4-cyanatophenyl) propane,
100 parts of (maleimidophenyl) methane are melted at 150 ° C.
The mixture was reacted for 4 hours with stirring to obtain a prepolymer. This was dissolved in a mixed solvent of methyl ethyl ketone and dimethylformamide. Add bisphenol A type epoxy resin (trade name: Epicoat 1001, Yuka Shell Epoxy Co., Ltd.)
) And 600 parts of a cresol novolac type epoxy resin (trade name: ESCN-220F, manufactured by Sumitomo Chemical Co., Ltd.) were uniformly mixed and dissolved. Further, as a catalyst, zinc octylate 0.4
Was added and dissolved and mixed. To this, 500 parts of an inorganic filler (trade name: calcined talc BST # 200, manufactured by Nippon Talc Co., Ltd.) was added, and uniformly stirred and mixed to obtain Varnish A. Apply this varnish to thickness 100
μm glass woven fabric, dried and gelled (at 170
C) 50 seconds, 170 ° C., 20 kgf / cm ² , a semi-cured prepreg B (FIG. 1, b) having an insulating layer thickness of 120 μm and having a resin flow of 10 mm in 5 minutes was obtained. On the other hand, Cu: 99.9%, Fe: 0.07%, P: 100 μm thick to become the inner metal plate (Fig. 1, c)
Prepare a 0.03% alloy plate, apply 25 μm of liquid etching resist on the upper and lower sides, dry it, and install the etching resist at the position where a clearance hole is formed at a place other than the central 13 mm square of the area to be a 50 mm square package To remove
Similarly, on the back surface, the etching resist in the clearance hole portion was removed, and etching was performed from both sides to form a clearance hole (p in FIG. 1) having a hole diameter of 0.65 mm. A black copper oxide treatment is applied to the entire metal plate, and one prepreg B is placed on each side of the metal plate, and a 12 μm electrolytic copper foil (FIG. 1, a) is placed outside the prepreg B, and 200 ° C., 20 kgf / cm ² , 30 mmHg
Laminate molding was performed for 2 hours under the following vacuum, and a resin was poured into the clearance hole portion to be filled and integrated.
In the center of the through hole, a 0.25 mm through hole (Fig. 1, e) is drilled so as not to contact the metal core.
Was drilled so as to reach the metal core, copper plating was performed after desmearing, and copper plating was performed on the through-holes (FIG. 1, m). Copper plating was also deposited on the front and rear via portions (FIG. 1, d) to fill all the holes (FIG. 1, l). Next, a circuit is formed on the front and back sides, and a plating resist is applied to portions other than the semiconductor chip mounting portion, the bonding pad portion on the front surface, and the ball pad portion on the rear surface (FIG. 1, k).
And plated with nickel and gold to form a printed wiring board. After bonding a 13 mm square semiconductor chip (FIG. 1, g) with a silver paste (FIG. 1, i) on a copper foil portion filled and plated in a via hole portion which is a semiconductor chip mounting portion on the surface. , Wire bonding (FIG. 1, h)
Next, a silica-containing epoxy sealing compound (FIG. 1,
Using f), the semiconductor chip portion, the wire portion, and the bonding pad portion were resin-sealed, and a solder ball (FIG. 1, J) was bonded to a solder ball pad on the back surface to produce a semiconductor package. This semiconductor plastic package was joined to an epoxy resin motherboard printed wiring board by melting solder balls. Table 1 shows the evaluation results.

Comparative Example 1 Two prepregs B (FIG. 2, b) of Example 1 were used, and 12 μm electrolytic copper foils (FIG. 2, a) were arranged on the upper and lower sides.
Laminate molding was performed for 2 hours under a vacuum of kgf / cm ² and 30 mmHg or less to obtain a double-sided copper-clad laminate C. Drilled through holes with a hole diameter of 0.25mmφ at predetermined positions and plated with copper (Fig. 2,
m). Circuits were formed on and under the plate by a known method, and were covered with a plating resist (FIG. 2, k), and then plated with nickel and gold. In this method, through holes (FIG. 2, n) for heat radiation are formed at a place where a semiconductor chip is mounted, and a semiconductor chip (FIG. 2, g) is formed thereon with a silver paste (FIG. 2, i).
Is bonded, and after wire bonding, resin sealing is performed with an epoxy sealing compound (FIG. 2, f) in the same manner as in Example 1.
Solder balls (FIG. 2, j) were joined (FIG. 2). Similarly joined to the motherboard. Table 1 shows the evaluation results.

Comparative Example 2 Epoxy resin (trade name: Epicoat 5045) 700 parts, epoxy resin (trade name: ESCN220F) 300 parts, dicyandiamide 35
Part, 2-ethyl-4-methylimidazole (1 part) was uniformly dissolved in a mixed solvent of methyl ethyl ketone and dimethylformamide, impregnated in a 100 μm-thick glass woven fabric, dried, and gelled (at 170 ° C.) for 10 seconds. A no-flow prepreg (prepreg D) having a resin flow of 98 μm, a high flow prepreg (prepreg E) having a gel time of 150 seconds and a resin flow of 18 mm were prepared. Using two prepregs E, an electrolytic copper foil of 12 μm was placed on the upper and lower sides, and laminated and formed at 190 ° C., 20 kgf / cm ² , and a vacuum of 30 mmHg or less for 2 hours to prepare a double-sided copper-clad laminate. Thereafter, a printed wiring board was prepared in the same manner as in Comparative Example 1, the semiconductor chip mounting portion was cut out using a counterbore machine, and a copper plate having a thickness of 200 μm (FIG. 3, c) was formed on the back surface using the no-flow prepreg D (FIG. 3). , O) were punched out and bonded in the same manner under heat and pressure to produce a printed wiring board with a heat sink. This slightly warped. A semiconductor chip (FIG. 3, FIG. 3,
g) were adhered, connected by wire bonding, and sealed with a liquid epoxy sealing resin (FIG. 3, f) (FIG. 3). Similarly, it was joined to a motherboard printed wiring board. Table 1 shows the evaluation results.

[0029] Table 1 Item implementation example comparisons Example 1 1 2 Heat resistance A after moisture absorption) normal state No change No change No change 24hrs. No abnormality No abnormality No abnormality 48hrs. No abnormality No abnormality No abnormality 72hrs. Abnormality None No abnormality No abnormality 96hrs. No abnormality No abnormality Partially peeled 120hrs. No abnormality Partially peeled partially peeled 144hrs. No abnormality Partially peeled partially peeled 168hrs. No abnormality Partially peeled partially peeled Heat resistance after moisture absorption B ) Normal condition No abnormality No abnormality No abnormality 24hrs. No abnormality Partial peeling Partial peeling 48hrs. No abnormality Large peeling Large peeling 72hrs. No abnormality Wire breakage Wire breakage 96hrs. No abnormality Wire breakage Wire breakage 120hrs. No abnormality Wire breakage Wire Out of 144hrs. No abnormality--168hrs. No abnormality--Glass transition temperature (° C) 234 234 160 Heat dissipation (° C) 35 56 48

<Measurement method> 1) Heat resistance after moisture absorption A) JEDEC STANDARD TEST METHOD A113-A LEVEL3: 30 ℃ ・ 60%
After the treatment with RH for a predetermined time, the presence or absence of an abnormality in the substrate after three cycles of reflow soldering at 220 ° C. was confirmed by cross-sectional observation and electrical check. 2) Heat resistance after moisture absorption B) JEDEC STANDARD TEST METHOD A113-A LEVEL2: 85 ℃ ・ 60%
After processing at RH for a predetermined time (Max. 168 hrs.), The presence or absence of abnormality in the substrate after three cycles of reflow soldering at 220 ° C. was confirmed by cross-sectional observation and electrical check. 3) Glass transition temperature Measured by the DMA method. 4) Heat dissipation The package was adhered to the same motherboard printed wiring board with solder balls and used continuously for 1000 hours before measuring the package temperature.

[0031]

According to the present invention, a metal plate having substantially the same size as the printed wiring board is disposed substantially at the center of the printed wiring board in the thickness direction, and the metal plate and the circuit conductors on the front and back surfaces are bonded to each other by a thermosetting resin composition. In the method of manufacturing a printed wiring board with a metal core having a structure in which at least the circuit conductors on the front and back surfaces are connected by through-hole conductors insulated with a thermosetting resin composition,
In the metal plate, in advance, at least at a position where a through hole is formed, a clearance hole or a slit hole is formed, and then, on both sides of the metal plate, a prepreg, a resin sheet, a coating film, or a metal foil with a resin is arranged, Place the metal foil on the outside of the resin layer where the metal foil is not attached, heat,
While making a metal foil-clad laminate with a metal core integrated by lamination molding under pressure, with a thermosetting resin composition, embed the holes formed in the metal plate, and further drill holes for through holes, Drill a via hole for heat radiation on the front and back to reach the metal core from the surface layer, perform desmear treatment if necessary, perform metal plating on the through hole, and further deposit metal plating on the via hole. By filling a metal, forming a solder resist layer on selected portions of the front and back, and applying a noble metal plating to the exposed metal surface, a printed wiring board having a novel structure could be manufactured. Using this printed wiring board, a semiconductor chip is adhered to the surface with a heat conductive adhesive, wire-bonded, resin-sealed, and epoxy resin mother board printed wiring board,
The semiconductor plastic package in which the solder balls are melt-bonded to the solder ball pads on the back side has a metal core that prevents moisture absorption from the back side, so the heat resistance after moisture absorption, that is, the popcorn phenomenon, has been greatly improved, and the heat dissipation is also improved. Excellent, in addition to mass productivity, improved economics,
A printed wiring board for a semiconductor plastic package containing a metal core having a novel structure was obtained.

[Brief description of figures]

FIG. 1 is a diagram illustrating a manufacturing process of a printed wiring board with a metal core according to a first embodiment and an explanatory diagram of a semiconductor plastic package using the same.

FIG. 2 is a manufacturing process diagram of a semiconductor plastic package of Comparative Example 1.

FIG. 3 is a manufacturing process diagram of a semiconductor plastic package of Comparative Example 2.

[Explanation of symbols]

 a metal foil b prepreg B c metal plate d hole for via hole e hole for through hole f sealing resin g semiconductor chip h bonding wire i silver paste j solder ball k plating resist l via hole filled with metal plating m front and back circuit Through hole for conduction n Through hole for heat dissipation o Prepreg D p Clearance hole

Claims (3)

[Claims] 1. A thermosetting resin composition in which a metal plate having substantially the same size as a printed wiring board is disposed at a substantially central portion in a thickness direction of the printed wiring board, and the metal plate and a circuit conductor on the front and back sides are arranged. In the method of manufacturing a printed circuit board with a metal core having a structure in which at least the circuit conductors on the front and back surfaces are connected by through-hole conductors insulated with a thermosetting resin composition, A clearance hole or a slit hole is formed at a position where a through hole is to be formed, and then a prepreg, a resin sheet, a coating film, or a resin-coated metal foil made of a thermosetting resin composition is placed above and below the metal plate. A metal foil is placed on the outside of the resin layer to which no metal is adhered, and a laminated metal foil with a metal core is formed by laminating under heat and pressure, and a thermosetting resin composition is used. Fill the clearance holes or slit holes formed in the metal plate, further drill holes for through holes so that they do not contact the metal core, drill holes for heat dissipation on the front and back surfaces, After processing and filling the drilled via holes with metal plating, the through-holes are electrically connected between the front and back, then a circuit is formed on the front and back metal foil, and at least the semiconductor chip mounting part and the bonding pad part And a method of manufacturing a printed wiring board with a metal core, which is obtained by coating a plating resist except for a ball pad portion and then applying a noble metal plating. 2. The method for producing a printed wiring board with a metal core according to claim 1, wherein said metal plate is a copper alloy or pure copper containing 95% by weight or more of copper. 3. The method according to claim 1, wherein the thermosetting resin composition is a polyfunctional cyanate ester resin composition.