JP2001102491A - Printed wiring board for ultra-thin bga semiconductor plastic package - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prepare a printed wiring board for a ultra-thin BGA semiconductor plastic package, which is excellent in rigidity modulus, ball shear strength, heat resistance electrical insulation after moisture absorption, migration resistance, etc. SOLUTION: In the printed wiring board for a ultra-thin BGA semiconductor plastic package, a circuit board is prepared using a glass cloth base single sided copper clad beard having an insulating layer of a thickness of 40-150 μm as a substrate of the semiconductor plastic package, a semiconductor chip bonding terminal is prepared on a side of the circuit board provided with the surface copper foil, a pad for solder ball connection is prepared on the copper foil with via holes, and a solder ball is melted in the via hole and bonded thereto. As a result, there can be obtained a printed wiring board which is good in ball share strength and workability.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention
The present invention relates to a printed wiring board for a chip scale package, which is mounted on a small printed wiring board having substantially the same size. The obtained printed wiring board has a semiconductor chip mounted thereon and is used for applications such as microcontrollers, ASICs, and memories. A package using this printed wiring board is connected to a motherboard printed wiring board using solder balls and used as an electronic device or the like.

[0002]

2. Description of the Related Art Conventionally, a chip scale package (CSP)
As the base material, a thin plate such as a glass epoxy material, a polyimide film material, and a ceramic material is mainly used.
These packages have a solder ball spacing of 0.8m
m or more, the solder ball pitch and circuit line / space have become increasingly narrower in recent years in order to reduce the thickness, size, and weight, and the board has heat resistance, electrical insulation after moisture absorption, migration resistance, etc. Was a problem. In addition, conventional plastic ball grid arrays (P-BG
A), the adhesion of the solder ball such as CSP to the substrate becomes weaker as the area of the solder ball pad becomes smaller,
This causes various defects.

[0003]

SUMMARY OF THE INVENTION The present invention provides a printed wiring board for a CSP in which the above problems are improved.

[0004]

SUMMARY OF THE INVENTION The present invention uses a single-sided copper-clad laminate of a glass cloth base material having an insulating layer thickness of 150 μm to 40 μm as a substrate of a semiconductor chip scale package. A solder ball connection pad is placed on the copper foil surface at the bottom of the chip bonding terminal and via hole, and a via hole is drilled from the base resin surface side to the point where the solder ball is connected until it reaches the back surface of the front copper foil To provide printed wiring boards for ultra-thin BGA type semiconductor plastic packages. After forming the via holes, a liquid phase process such as a desmear process and a gas phase process such as a plasma process may be performed as necessary. ADVANTAGE OF THE INVENTION According to this invention, the ball shear strength is strong, workability | operativity is favorable, and the ultrathin printed wiring board is provided at low cost.

[0005]

BEST MODE FOR CARRYING OUT THE INVENTION The glass cloth substrate used in the present invention preferably has a thickness of 50 ± 10 μm and a weight of 35 to 60 g / m 2.
^2, and air permeability of 25cm ³ / cm ² · sec. The following fabric is used. By using such a woven fabric, the rigidity of the glass woven fabric is improved, and by further adding an inorganic filler to the resin composition, a further improvement in the rigidity can be achieved, and processing defects during work are reduced. Become. Via holes for solder ball connection
A laser, preferably a carbon dioxide gas laser, is opened from the glass cloth substrate reinforcing resin side, and at least a semiconductor chip bonding terminal is formed on the surface copper foil surface, and a solder ball connection pad is formed on the bottom side via hole bottom copper foil. After that, a desmear treatment or a plasma treatment is performed, and if necessary, nickel plating or gold plating is performed after coating with a plating resist to obtain a printed wiring board.

As the resin used for the single-sided copper-clad laminate, a polyfunctional cyanate ester and a thermosetting resin composition containing the cyanate ester prepolymer as an essential component are preferably used. Use of this resin composition is excellent in properties such as heat resistance, electrical insulation after moisture absorption, and migration resistance.
Contributes to the provision of printed wiring boards for P. The present invention provides a substrate for a semiconductor chip scale package,
Using a single-sided copper-clad laminate with a glass cloth substrate with an insulating layer thickness of 150 μm to 40 μm, make a via hole to connect the solder ball pad from the resin side to the back side of the surface copper foil, and if necessary, desmear treatment , Vapor phase treatment, etc., forming at least semiconductor bonding terminals on the front side, solder ball connection pads on the back side, coating with plating resist if necessary, then nickel plating and gold plating to create printed wiring boards I do.

[0007] The printed wiring board of the present invention has a high rigidity and is easy to handle because it is a glass cloth reinforced base material compared to a soft film such as a polyimide film base material because the manufacturing process is simple. In addition, when the solder balls are bonded, there is an advantage that the connection is simple, the bonding strength of the solder balls is strong, and the peel strength (ball shear strength) of the solder balls is excellent.

The single-sided copper-clad laminate of the present invention includes a single-sided copper-clad laminate obtained by impregnating a generally known glass cloth with a thermosetting resin and drying, and also includes a single-sided copper-clad multilayer plate. . As glass fiber, generally known glass fiber,
For example, woven fabrics of glass fibers such as E, N, S, and D,
Generally, a thickness of 30 to 150 μm is used. Also, a blending using these yarns can be used. As the substrate, those having high density are preferable, and preferably, the thickness is 50 ± 10 μm, and the weight is 35 to 6 μm.
One or more, preferably two or more woven fabrics each having 0 g / m ² and having an air permeability of 25 cm ³ / cm ² · sec. Or less are used. There is no particular limitation on the weave, but plain weave is preferred. By using this fabric, the air permeability is 25 cm ³ which is the conventional fabric.
/ Cm ² · sec., Higher rigidity, less bending during processing, and better workability. In addition, there is an advantage that the hole wall becomes uniform when a via hole is formed by a laser from the resin-coated base material layer.

As the resin of the thermosetting resin composition used in the present invention, generally known thermosetting resins are used. Specifically, an epoxy resin, a polyfunctional cyanate ester resin, a polyfunctional maleimide-cyanate ester resin, a polyfunctional maleimide resin, a polyimide resin, an unsaturated group-containing polyphenylene ether resin, etc. Two or more types are used in combination. Heat-resistant,
A polyfunctional cyanate resin composition is preferred in terms of 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-cy (Anatophenyl) phosphite, tris (4-cyanatophenyl) phosphate, and cyanates obtained by reacting novolak with cyanogen halide.

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 the reaction of a polyol, a hydroxyl-containing silicone resin with an ephalohydrin, and the like. These are one or two
More than one type may be used in combination.

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, and natural rubber; polyethylene, polypropylene, polybutene, poly-4-methyl Pentene, polythrene, 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 appropriately used. In addition, other known organic fillers, dyes, pigments, thickeners, lubricants, defoamers, dispersants, leveling agents, photosensitizers, flame retardants, brighteners, polymerization inhibitors, thixotropic agents And various other additives are used in combination as needed. If necessary, the compound having a reactive group is a curing agent,
A catalyst is appropriately blended.

The thermosetting resin composition of the present invention can be cured by heating itself, but has a low curing rate and is inferior in workability and economic efficiency. Can be used. The amount used is 0.005 to 10 parts by weight, preferably 0.01 to 5 parts by weight, per 100 parts by weight of the thermosetting resin.

The rigidity can be further increased by adding an inorganic filler to the resin composition. The method of mixing the inorganic filler in the resin composition is not particularly limited, for example, a bead mill, a homomixer, a ball mill,
Generally known methods can be used. As the inorganic insulating filler, generally known ones can be used. Specifically, natural silica, calcined silica, silica such as amorphous silica, white carbon, titanium white, aerosil, clay, talc, wollastonite, natural mica,
Kaolin, alumina, perlite, aluminum hydroxide, magnesium hydroxide and the like can be mentioned, and one kind or a combination of two or more kinds can be used. The amount added is 10 to 80% by weight, preferably 20 to 70% by weight of the total composition. Particles having an average particle size of 1 μm or less are preferred.

The glass cloth substrate-reinforced copper-clad laminate is first impregnated with a thermosetting resin composition and dried to form a B stage to prepare a prepreg. Next, a copper foil is disposed on one side of the prepreg, and a release film is disposed on the opposite side, and laminated under heat, pressure, or preferably under vacuum to form a single-sided copper-clad laminate. Moreover, the multilayer board can also be used. For example, after forming a circuit on one side of a double-sided copper-clad laminate, subjecting it to a chemical treatment if necessary, placing a prepreg on the circuit forming side and placing a release film on the outside, heating, pressing, and vacuuming It is made by laminating below.

The copper foil used is not particularly limited, but preferably the outer layer copper foil is 18 to 35 μm and the inner layer copper foil is 18 to 70 μm. The surface treatment of the copper foil is not particularly limited, and examples thereof include an alloy treatment of nickel, zinc, or the like.

Finally, the glass-clad base material single-sided copper-clad laminate prepared so as to have an insulating layer thickness of 40 to 150 μm is formed with a via hole from the base resin surface side to form a surface or inner layer copper foil. Make it reach the back side. The diameter of the via hole is equal to or slightly smaller than the diameter of the solder ball. Generally, the pore size is 200 to 800 μm.

There is no particular limitation on the method of making holes, and lasers such as carbon dioxide laser, excimer laser, and YAG laser; blasts such as wet blast and dry blast; machines such as routers and drills are generally known. Method. A carbon dioxide laser is preferred from the viewpoint of the processing speed and the subsequent formation of a control circuit. The circuit may be formed either before or after drilling. It is appropriately selected depending on the method of drilling.

A resin layer remains on the surface of the copper foil at the bottom of the via hole formed to reach the opposite surface or the inner layer copper foil, depending on the drilling method. Examples of a method for removing the resin layer include a gas phase treatment such as a plasma treatment and a wet treatment such as a desmear treatment. This processing is preferably performed after a circuit is formed on the surface layer.

After the circuit is formed, nickel plating or gold plating is applied to the entire surface as it is, or the circuit is covered with a plating resist except for at least the wire bonding terminals, and then nickel plating and gold plating are performed.

The solder ball is placed above the via hole, heated and melted, and the solder ball is poured into the via hole, and at the same time, the air is released to join the solder ball to the solder ball connection pad on the back side of the surface copper foil.

[0024]

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
Then, the mixture was dissolved and mixed, and uniformly stirred and mixed to obtain Varnish A. This varnish is impregnated with a glass woven fabric having a thickness of 50 μm and a weight of 53 g / m ² , dried at 150 ° C., and subjected to a gelation time (at 170 ° C.)
At 0 seconds, prepreg B having a resin composition content of 51% by weight was prepared.

An electrolytic copper foil having a thickness of 35 μm was placed on one side of the two pieces of the prepreg B, and a release film was placed on the other side at 200 ° C., 20 kgf / cm ² , and a vacuum of 30 mmHg or less. Lamination molding was performed for a time to obtain a single-sided copper-clad laminate (FIG. 1 (1)).
From the resin surface side, a 300 μm diameter carbon dioxide laser was irradiated for 6 shots at an output of 50 μs to make a hole reaching the back side of the copper foil (Fig. 1 (2)). Then, the thickness of the 35 μm copper foil was reduced with a chemical solution. Etching was performed to a thickness of 12 μm to reduce the thickness (FIG. 1 (3)), and a circuit was formed on the copper foil. Then, a resin residue at the bottom of the via hole is removed by a desmear treatment, and the terminal is covered with a plating resist except for the semiconductor chip bonding terminals (FIG. 1, e), and is plated with nickel and gold to obtain a printed wiring board ( FIG. 1 (4)). A semiconductor chip was bonded onto this printed wiring board with a silver paste, wire-bonded, and then sealed with an epoxy sealing resin (FIG. 1).
(5)). After encapsulating the resin, turn it over, place a solder ball with a diameter of 400μm over the via hole, heat and melt it, fill the via hole with solder, and connect the solder ball to form a plastic package (Fig. 1 (6)). Table 1 shows the evaluation results of the plastic package.

Example 2 To the varnish A of Example 1, 2,000 parts of an inorganic filler (trade name: talc, manufactured by Nippon Talc Co., Ltd.) was added and uniformly mixed with a homomixer. This is 35 μm thick and weighs 41 g /
Impregnated in glass woven fabric with m ² and air permeability of 5.3 cm ³ / cm ² · sec, dried and gelled for 110 seconds, prepreg C with a resin composition content of 58% by weight, gelled for 122 seconds, resin composition Material content 65 weight
% Prepreg D was made. An 18 μm electrolytic copper foil was placed on the front and back of one prepreg C, and was similarly laminated and formed to produce a double-sided copper-clad laminate. A circuit is formed on both sides, black copper oxide treatment is applied, prepreg D is placed on both outer sides, and 3 μm with a 35 μm thick copper carrier is provided on one outer side.
, A release film was disposed on the opposite side, and the laminate was formed in the same manner. Thereafter, the release film and the carrier copper foil of 35 μm were peeled off to form a three-layer plate. The thickness of the insulating layer was 140 μm in total.

The beam diameter is 250 μm from the resin surface side of the three-layer plate.
The carbon dioxide laser was irradiated for 5 shots at an output of 50 μs to make a via hole reaching the inner layer copper foil. The inner layer copper foil and the surface layer copper foil are connected by a mechanical drill with a hole diameter of 200 μm, copper plating is performed 15 μm, a circuit is formed on the surface copper foil on the opposite side, plasma vapor processing is performed, and the via hole bottom is formed. The resin layer adhering on the surface of the inner copper foil was removed.
A plating resist was attached to portions other than the semiconductor chip mounting portion and the bonding pad portion, and nickel plating and gold plating were similarly applied to obtain a printed wiring board. The diameter of this via hole is 35
A 0 μm solder ball was connected in the same manner as in Example 1 to obtain a semiconductor plastic package. Table 1 shows the evaluation results.

Example 3 700 parts of an epoxy resin (trade name: Epicoat 5045, Yuka Shell Epoxy Co., Ltd.) and an epoxy resin (trade name: ESCN2)
20F, Sumitomo Chemical Co., Ltd.) 300 parts, dicyandiamide 35
And 1 part of 2-ethyl-4-methylimidazole was dissolved in a mixed solvent of methyl ethyl ketone and dimethylformamide, and uniformly stirred and mixed to obtain Varnish E. To this, 1100 parts of the inorganic filler of Example 1 was added and uniformly dispersed. this,
Thickness 120 [mu] m, weight 135 g / m ^2, impregnated with air permeability 3.3cm ³ / cm ² · sec. Woven glass fabric, dried, gel time 151 seconds, the prepreg F resin composition content of 57 wt% Created. Using one piece of this prepreg F, a copper foil having a thickness of 18 μm
A single-sided copper-clad laminate was prepared by laminating at 0 ° C., 20 kgf / cm ² , and a vacuum of 30 mmHg or less for 2 hours. After forming the circuit, place a 400 mm diameter
A metal plate having a hole of μm was placed in close contact therewith, and a hole was formed from above by a wet sandblast method so as to reach the back side of the copper foil surface to form a via hole. After removing the blast powder etc. remaining in this hole by soft etching,
Nickel plating and gold plating were adhered to the entire surface to obtain a printed wiring board. A semiconductor chip was adhered thereon with a silver paste, resin-sealed after wire bonding, and then turned over, and solder balls having a diameter of 500 μm were similarly filled and adhered to obtain a semiconductor plastic package.
Table 1 shows the evaluation results.

Comparative Example 1 The same prepreg B as used in Example 1 was used, and a 12 μm electrolytic copper foil was placed on both sides of the prepreg B. I got a board. After drilling a hole with a hole diameter of 200 μm with a mechanical drill, applying a copper plating with a thickness of 15 μm on the whole, a circuit is formed on the front and back surfaces, a semiconductor chip wire bonding pad on the front surface, a circuit, and a 400 μm ball on the back surface. A pad and a circuit connecting the pad were formed, and a plating resist was adhered except for a wire bonding pad on the surface, and nickel plating and gold plating were performed to obtain a printed wiring board. Thereafter, a semiconductor plastic package having a solder ball having a diameter of 400 μm bonded to the back surface was similarly formed. Table 1 shows the evaluation results.

Comparative Example 2 In Example 3, the epoxy resin (trade name: Epicoat 5045) 1,00 was used instead of 700 parts and 300 parts of the epoxy resin.
A varnish G was prepared in the same manner as in Example 3 except that 0 part was blended. No inorganic filler was blended in the varnish. This varnish G is 100 μm thick, weighs 100 g / m ² , and has an air permeability of 38 cm ³ / c.
A prepreg H having a resin composition content of 47% by weight and a gel time of 113 seconds was prepared by impregnating and drying a glass woven fabric of m ² · sec. Use one prepreg, 12μ on both sides
m copper foil was placed and similarly laminated and formed to produce a double-sided copper-clad laminate (FIG. 2 (1)). Otherwise, a printed wiring board was prepared in the same manner as in Comparative Example 1 to obtain a semiconductor plastic package (FIG. 2 (6)). Table 1 shows the evaluation results.

[0032]

[Table 1]

[0033]

<Measurement method> 1) Glass transition temperature Measured by the DMA method. 2) Viscoelasticity It was measured by DMA using a laminate obtained by removing the copper foil by etching. 3) Insulation resistance after pressure cooker processing Create a comb pattern with line / space = 50 / 50μm,
On this, the prepregs respectively used were arranged, and the laminated and molded one was treated at 121 ° C. and 2 atm for a predetermined time,
Post-treatment was performed at 25 ° C. and 60% RH for 2 hours, and the insulation resistance value between the terminals was measured 60 seconds after 500 VDC was applied. 4) Migration resistance The test piece of 3) was applied at 85 ° C and 85% RH at 50 VDC, and the insulation resistance between the terminals was measured. 5) Ball shear strength Pressure was applied from the side of the ball, and the strength when peeled was shown. 6) Short circuit and cutting of circuit 200 lines / spaces = 50/50 μm were prepared, and the number of short circuits and cuts was shown in the numerator.

[0035]

According to the present invention, as a substrate of a semiconductor chip scale package, a thickness of 150 μm to 40 μm is provided.
Using a glass cloth base material single-sided copper-clad laminate having an insulating layer of m, at least a terminal for semiconductor chip bonding on the surface and a via hole from the resin surface side to the copper foil back side surface reach the copper foil back side of the surface. Provided is a printed wiring board on which solder ball connection pads are opened. After connecting the semiconductor chip to the surface by wire bonding and sealing it with the sealing resin, turn it over and melt the solder ball into the via hole, pour it in, and connect it to the copper foil surface at the bottom of the via hole on the back side of the surface copper foil I do. According to the printed wiring board of the present invention, the ball shear strength of the solder ball is high, and the workability is good. Also, as glass woven fabric, thickness 50 ± 10μm, weight 35 ~ 6
0g / m ² , air permeability 25cm ³ / cm ² · sec.
By using at least two sheets, preferably at least two sheets, the rigidity is high and workability is improved, and the rigidity can be further improved by adding an inorganic filler. In addition, by using a polyfunctional cyanate ester as the thermosetting resin composition and the cyanate ester prepolymer as essential components, a semiconductor having excellent heat resistance, electrical insulation after pressure cooker treatment, migration resistance, etc. A printed wiring board for a plastic package was obtained.

[Brief description of the drawings]

FIG. 1 is a manufacturing process diagram of a printed wiring board and a semiconductor plastic package of Example 1.

FIG. 2 is a manufacturing process diagram of a printed wiring board and a semiconductor plastic package of Comparative Example 2.

[Explanation of symbols]

 a Copper foil b Glass cloth base resin layer c Via hole drilled from insulating layer d Copper foil thinned by etching e Wire bonding pad section f Plating resist g Bonding wire h Sealing resin i Semiconductor chip j Silver paste k Solder ball l Copper-plated copper foil m Through hole for through hole

 ──────────────────────────────────────────────────続 き Continued on front page F-term (reference) 5E336 AA04 BB16 BC12 BC15 BC34 CC32 CC36 GG12

Claims (5)

[Claims] Using a glass cloth substrate single-sided copper-clad laminate having an insulating layer thickness of 150 μm to 40 μm, a via hole for connecting a solder ball from the substrate resin surface side reaches the back surface of the copper foil of the next layer. Ultra-thin BGA type semiconductor plastic package characterized by having at least a semiconductor chip bonding terminal on the surface copper foil side and a solder ball connection pad on the back side via hole copper foil formation surface For printed wiring boards. 2. A woven fabric having a thickness of 50 ± 10 μm, a weight of 35 to 60 g / m ² , and an air permeability of 25 cm ³ / cm ² · sec. Or less. 2. A printed wiring board for an ultra-thin BGA type semiconductor plastic package according to claim 1, wherein the printed wiring board is a glass woven fabric obtained by combining at least one of the following. 3. The ultrathin film according to claim 1, wherein the via hole formed from the resin surface side of the base material is manufactured by removing a glass cloth and a thermosetting resin composition by a laser. BG
Printed wiring board for A type semiconductor plastic package. 4. The thermosetting resin composition of the single-sided copper-clad laminate is a thermosetting resin composition containing a polyfunctional cyanate ester compound and the cyanate ester prepolymer as essential components. 4. The printed wiring board for an ultra-thin BGA type semiconductor plastic package according to 2 or 3. 5. The printed wiring for an ultra-thin BGA type semiconductor plastic package according to claim 1, wherein the resin composition of the single-sided copper-clad laminate contains 10 to 80% by weight of an insulating inorganic filler. Board.